Journal articles on the topic 'Radial slide bearing'

As the areal recording density increases in hard disk drives (HDDs), the flying physical spacing between the head and the disk decreases and the likelihood of head-disk contact during full speed rotation increases. Therefore, the simulation and modeling of the air bearing slider with ultra-low flying heights becomes an important issue for the operational shock simulation. The static/dynamic properties, including the influence of the radial position and the skew angle of the slider, the rotating speed of the disk, and the shock simulation, of the air bearing slider were analyzed. Generally speaking, for a given rotating speed of the disk, as the slider moves from the inner diameter to the outer diameter, the maximum contact pressure, the skew angle, the pitch angle, and the maximum air bearing pressure increase; while the flying height decreases. These trends are strengthened by a faster rotating speed of the disk. There are obvious oscillations in the air bearing force and the minimum spacing when contact occurs during a shock.

The purpose of this paper is to choose a new topology for bearingless flux-switching slice motors, regarding the number of stator and rotor poles, with a combined winding set. Additionally, the selected motor topology is optimized with finite element method (FEM) simulations to improve the performance. Bearingless slice drives feature a magnetically-suspended rotor disk passively stabilized by reluctance forces due to a permanent magnet (PM) bias flux in the air gap and actively controlled by the generation of radial bearing forces and motor torque. Usage of the combined winding set, where each phase generates both motor torque and suspension forces, opens the opportunity for a new topology. The topology choice and optimization are based on FEM simulations of several motor optimization criteria, as the passive axial, tilting and radial stiffness values and the active torque and bearing forces, which are simulated regarding the motor height and specific stator and rotor parameters. Saturation, cogging torque and cogging forces are also analyzed. The 3D FEM program ANSYS Maxwell 2015 was used. The results led to an optimized bearingless flux-switching motor topology with six new stator segments and seven rotor poles. By optimizing the geometry, a considerable improvement of performance was reached. This geometry optimization is a base for a future prototype model.

Previously, the contact states between the bearing and journal of a spatial revolute joint (SRJ) with both axial and radial clearances were solved in the global coordinate system (GCS), which is complex and requires iterations. In this paper, a local-coordinate representation for the SRJs with clearance is combined with a vector-form particle-element method, i.e. finite particle method (FPM), to provide a more practical means for evaluation of the dynamic effects due to clearance. Firstly, the fundamentals of the FPM for analysis of spatial mechanisms are briefed. Then, a local-coordinate representation based on the revolution axis of the bearing is proposed. Specifically, the geometry of the journal and bearing is explicitly expressed using the coordinate transformation. The axial and radial contact states are evaluated by substituting the parametric equations and transforming them to quadratic and quartic equations, respectively, which can be analytically solved without iterations. The contact forces are evaluated in the local-coordinate representation and then transformed into the GCS representation. Two numerical examples, i.e. a spatial slider-crank mechanism and a spatial double pendulum, are provided to demonstrate the feasibility of the proposed method, by which the effects of joint-joint interaction and joint-flexible component interaction are fully discussed.

The criteria of stressed state equivalence used for fatigue process simulation are shown. Different criteria offered by various investigators for slider bearings are described. A procedure is offered for the estimate of different criteria applicability on the basis of experimental investigation results. It is shown that for tin-based babbit layers it is possible to use the first basic stress as a criterion, but at that it is necessary to take into account a propping action of lubricant coming in a crack under pressure (radial stresses).

A comprehensive analytical investigation of the dynamic response of a general planar kinematic chain comprising an assemblage of articulating interconnected rigid-bodies with bearing clearances in the revolute joints is presented. The equations governing the dynamical behavior of this general mechanical system are established by incorporating a four-mode model of the phenomenological behavior of the principal elements of each revolute joint into the generalized form of Lagrange’s equations. The proposed methodology is then employed to predict the dynamic behavior of a planar slider-crank mechanism with radial clearance in the gudgeon-pin joint prior to comparing these theoretical predictions with the corresponding response-data from a complementary experimental investigation.

Purpose To improve the lubrication and tribology performance (LTP) of the crankpin bearing, this paper aims to propose the optimization of the crankpin bearing parameters considering effect of the high-speed dynamic load and micro asperity contact. Design/methodology/approach A numerical simulation method combined by the slider-crank-mechanism dynamic and lubrication models is applied to solve the dynamic and lubrication equations of crankpin bearing. These equations are then computed via an algorithm program written in Matlab software. The contact force (Wac) in the asperity contact region, friction force (Ff) and friction coefficient (μ) of crankpin bearing are chosen as objective functions. The original parameters and experimental data of the engine are used for the simulation to enhance the reliability of the research results. The parameters are then optimized to obtain the minimum values of Wac, Ff and μ. Findings The research results show that the LTP is significantly improved with optimized parameters. Particularly, the maximum values of Wac and Ff are greatly decreased by 27 and 32%, respectively. Originality/value Reducing the width, radius and surface roughness and increasing the radial clearance of crankpin bearing can improve better the LTP. Peer review The peer review history for this article is available at: https://publons.com/publon/10.1108/ILT-02-2020-0072/

A series of laboratory tests was performed to study the deformation and radial consolidation around end-bearing (fully penetrating) stone columns. For this purpose, the behaviour of a horizontal slice of a unit cell representative of a column and the surrounding soil was analysed. The tests were carried out in a Rowe–Barden large oedometric cell that was instrumented to measure vertical stresses and pore pressures at several distances from the axis. Two column geometries were tested, with cell-to-column diameter ratios of N = 3 and 4. The most important findings of this work were the rate of pore pressure dissipation, the vertical strain reduction due to the presence of the column of approximately 25% for N = 4 and 35% for N = 3, and the load transfer to the column related to the stiffness ratio between the column and soil resulting in incremental stress concentration factors in the range 2.5 to 9.2. Results were compared with theoretical solutions that are commonly used for the study of stone column behaviour.

The article presents research on the mechanical properties of a drive system using an innovative mechanism converting rotary motion to progressive motion. The operating principle of the mechanism uses the friction-based transmission of drive from the motor to the drive shaft by means of two oppositely arranged unidirectional clutches. A side effect of such a solution utilized in the mechanism is the possibility of shifting the couplings while transmitting torque. The clutches were combined with a mechanism converting rotational motion to linear motion by utilizing friction between radial ball bearings and the shaft. This has resulted in an innovative mechanism for converting rotary motion to progressive motion, with the drive source being bound with a “friction screw” (a “slide” screw). A characteristic feature of this solution is the fact that there is no need for the nut to rotate in order to achieve progressive movement. Known solutions are based on a rotating nut and a fixed shaft system. The mechanism uses a fixed pitch nut, but it is possible to use a regulated pitch nut as a possible modification of the mechanism at a later stage of the system development. The main advantage of the mechanism tested is the possibility of uncoupling, which occurs when the maximum force transmitted by the nut is exceeded. This force is related to the friction force resulting from the pressure exerted by angularly shifted ball bearings on the drive shaft. The bearings are a substitute for the screw line in the classical ball screw mechanism. The research results presented in the article give an overview of the mechanical properties of the solution developed. The article also presents the influence of rotational speed and load on the mechanical parameters of the drive. The application of the described invention as the basis of the linear motion mechanism driving the tool of a surgical robot is a safe solution with unique and desirable characteristics.

This study presents experimental results on the effect of out-of-contact lubricant channeling on the tribological performance of nonconformal contacts under starved lubrication. Channeling of lubricant was carried out by adding a slider with a limited slot for scraping the displaced lubricant on one of mating surfaces (ball). Thus, the scraped lubricant is forced to flow back into the depleted track through the limited slot resulting in robust replenishment. The measurements have been conducted using optical tribometer (ball-on-disc) equipped with a digital camera and torque sensor. The effect of lubricant channeling was compared to the original contact condition by means of measuring friction and film thickness. The results show that the out-of-contact lubricant channeling leads to a significant enhancement of film thickness and friction reduction under starved conditions. Indeed, the starved elastohydrodynamic lubrication contacts transformed to the fully flooded regime after introducing the flow reconditioning. Moreover, the film thickness decay over time, which is common with starved elastohydrodynamic lubrication contacts, has not been observed in the case of lubricant channeling. However, the beneficial effect of lubricant channeling diminishes as the original contact condition tends to the fully flooded regime. The results of this study can be easily implemented in practical applications such as radial and thrust rolling-element bearings.


 Laryngeal SCCA usually presents with hoarseness when the glottis is involved, dysphagia if the supraglottis is involved, and difficulty of breathing and stridor in subglottic invovlement. A neck mass as an initial presentation of laryngeal carcinoma is commonly linked to the involvement of the supraglottis due to its rich lymphatic drainage. About 70% of supraglottic tumours present with advanced disease (stages III-IV),1 while 75% of glottic tumours present with localized disease (stages I-II).1
 Smoking and alcohol consumption are considered highly significant etiologic factors but evidence has suggested a possible role for human papilloma virus (HPV) infection, ras oncogene activation, and gastroesophageal reflux as well.2 To the best of our knowledge, laryngeal squamous cell carcinoma has not been associated with herpes simplex virus (HSV).
 We report a case of laryngeal squamous cell carcinoma with an unusual presentation and peculiar histopathology, and discuss its potential association with herpes simplex virus.
 
 CASE REPORT
 
 A 67-year-old man consulted for a right lateral neck mass that gradually started enlarging eight months prior to consult. There was no fever, cough, nasal discharge or congestion, hoarseness, dysphagia, difficulty of breathing, weight loss, oral ulcers, difficulty opening and closing the mouth, or facial asymmetry, and he did not consult a health professional or take any medication. He was a smoker but did not drink alcoholic beverages. He finally consulted due to the gradual increase in size of the neck mass.
 Physical examination revealed a 6 x 7 cm hard, fixed, right neck mass involving levels II, and III. Flexible endoscopy showed an enlarged right arytenoid with normal-looking mucosa. (Figure 1 A, B). A CT scan of the neck revealed a 2.8 x 3.8 x 6.3 cm supraglottic/glottic soft tissue mass and right-sided cervical lymphadenopathies suggestive of metastasis. (Figure 2 A, B) Direct laryngoscopy with biopsy of the (arytenoid) supraglottic mass and panendoscopy surprisingly revealed only an enlarged right arytenoid and no lesions in the false and true vocal folds or oral, nasopharyngeal, oropharyngeal, tracheal, and esophageal mucosa. Histopathology showed focal moderate dysplasia with cytopathic changes probably Herpes Simplex virus infection with probable involvement of the submucosal layer requiring deeper bites for further diagnosis.
 At this point, although the working impression was a benign lesion, we still considered the possibility that this was a malignancy because of the dysplastic changes noted on the histopathology report. A repeat laryngoscopy with biopsy of the supraglottic mass and fine needle aspiration biopsy of the neck mass yielded a histopathologic diagnosis of moderately differentiated squamous cell carcinoma and level II lymph node metastatic SCCA. With a diagnosis of laryngeal SCCA stage IVA (T3 N2b M0), a total laryngectomy with bilateral neck dissection (radical on the right and modified radical on the left) and total thyroidectomy was performed. There was a submucosal lesion confined to the supra and glottic area on the right side of the posterior aspect of the cut larynx. (Figure 3) Final histopathology showed moderately differentiated, keratinizing invasive squamous cell carcinoma with viral cytopathic changes. (Figure 4)
 
 DISCUSSION
 In this case, the patient initially presented with a lateral neck mass without associated signs and symptoms. This made it more difficult to diagnose, since neck masses can have varying etiologies involving a large number of different structures of the head and neck. Squamous cell carcinoma on physical examination usually presents with an ulcerative, exophytic, or polypoid lesion.2 This patient initially showed an enlarged right arytenoid with normal-looking mucosa and no involvement of the false and true vocal folds, consistent with the absence of symptoms of hoarseness or dysphagia. Considering the patient’s age and the history of smoking, a malignant neoplasm was still the most plausible explanation for the lateral neck mass and supraglottic bulge. Imaging was important to evaluate deeper structures that might be involved. Computed tomography is an indispensable tool for evaluating submucosal laryngeal masses or otherwise unexplainable symptoms (usually hoarseness) that might herald such a mass.3 CT scans showed involvement of the supraglottis and glottis, inconsistent with the patient’s history and physical examination findings. 
 Our patient was diagnosed to have transglottic SCCA with paraglottic space (PGS) involvement. Paraglottic space involvement in either a glottic or supraglottic tumor is staged as T3 and is significant because the extent of the PGS means that tumors in this space may spread to involve any or all of the three regions of the larynx.2 The PGS lies lateral to the true and false vocal folds and extends laterally to the thyroid cartilage.2 Anteriorly, each PGS is continuous with the paraepiglottic space, and tumors may spread along this pathway.2 
 Transglottic tumors are an important subset of laryngeal tumors with aggressive behavior and high risk of lymphatic metastasis. The term transglottic was first used by McGavran and associates in 1961.4 It is not used in the American Joint Commission and associates for Cancer (AJCC) staging system and is defined by Kirchner and colleagues as a tumor that crosses the ventricle in a vertical direction.4 Tumors can become transglottic in four ways: by crossing the ventricle directly; by crossing at the anterior commissure; by spreading through the paraglottic space; and by spreading along the arytenoid cartilage posterior to the ventricle. The latter form of spread does not predict deep invasion: in Kirchner's series of 50 transglottic tumors studied in whole organ preparations, none of the 8 tumors with transglottic spread along the arytenoid demonstrated laryngeal cartilage invasion.4 In the same series, invasion of the laryngeal framework was seen in over half of transglottic tumors over 2 cm. Cervical metastases were seen in 30% of cases; and in primary tumors greater than 4 cm in dimension, 55% of tumors had nodal metastases.4
 The biopsy showed moderate dysplasia with viral cytopathic changes suggestive of submucosal rather than mucosal involvement, and this was consistent with our intraoperative findings. In general, squamous cell carcinomas histologically involve the epithelial layer of a certain structure. However, in a specific type of laryngeal carcinoma -- ventriculosaccular squamous cell carcinoma -- epithelial lesions are not visibly apparent.2 Our case may have been similar to ventriculosaccular SCCA in this regard.
 The histopathologic slides of our patient revealed multinucleated giant cells, which resulted from fusion of cell membranes bearing viral glycoproteins. (Figure 4) Alterations in the cell nuclei and cytoplasmic tails between the cells were seen. These cytopathic effects (CPE) are seen in HSV-infected cells. This is another issue because Herpes viruses are less likely linked to laryngeal malignancies. Herpes simplex virus (HSV) is less strongly correlated with the development of oral carcinomas than EBV or HPV.5 On the other hand, serologic studies have shown that patients with head and neck cancer have higher levels of IgM antibody to HSV type one than control ‘subjects.6,7 HSV can transform cells in vitro to a malignant phenotype. This may be due to an HSV-encoded peptide that increases mutagenicity of infected cells. In one series of 31 young adults with head and neck cancer, antipeptide antibody levels were significantly higher in the patients than in control subjects.8 However, most of the studies generalized the association of viruses with malignancies of the oral cavity in general, not with laryngeal carcinoma alone. The question regarding which caused which is left; did the Herpes virus cause the laryngeal SCCA or was it a superimposed infection due to the patient’s immunocompromised state?
 Head and neck carcinomas are closely linked to Epstein-Barr and Human Papilloma viruses, particularly carcinoma of the nasopharynx and the oral cavity respectively. At present, accepted causal associations between viruses and human cancer include HPV and cervical cancer; human T-lymphotrophic virus type-1 (HTLV-1) and adult T-cell leukemia and lymphoma; hepatitis B and C and liver cancer, Epstein–Barr virus (EBV) and nasopharyngeal cancer, Burkitt’s and Hodgkin’s lymphomas, and some non-Hodgkin’s lymphomas; and human herpes virus 8 (HHV-8) and Kaposi’s sarcoma.9
 There may or may not be an association between herpes simplex virus and laryngeal SCCA, but our experience suggests that the matter is worth investigating. The clinical history and physical examination findings may not always reveal the true extent of disease, and imaging modalities may mislead, but the complementary nature of all these should be considered vis-à-vis intraoperative findings and final histopathologic results.
 
 
 
 
 
 


 
 
 On the morning of Thursday, 4 May 2006, the United States House Permanent Select Committee on Intelligence held an open hearing entitled “Terrorist Use of the Internet.” The Intelligence committee meeting was scheduled to take place in Room 1302 of the Longworth Office Building, a Depression-era structure with a neoclassical façade. Because of a dysfunctional elevator, some of the congressional representatives were late to the meeting. During the testimony about the newest political applications for cutting-edge digital technology, the microphones periodically malfunctioned, and witnesses complained of “technical problems” several times. By the end of the day it seemed that what was to be remembered about the hearing was the shocking revelation that terrorists were using videogames to recruit young jihadists. The Associated Press wrote a short, restrained article about the hearing that only mentioned “computer games and recruitment videos” in passing. Eager to have their version of the news item picked up, Reuters made videogames the focus of their coverage with a headline that announced, “Islamists Using US Videogames in Youth Appeal.” Like a game of telephone, as the Reuters videogame story was quickly re-run by several Internet news services, each iteration of the title seemed less true to the exact language of the original. One Internet news service changed the headline to “Islamic militants recruit using U.S. video games.” Fox News re-titled the story again to emphasise that this alert about technological manipulation was coming from recognised specialists in the anti-terrorism surveillance field: “Experts: Islamic Militants Customizing Violent Video Games.” As the story circulated, the body of the article remained largely unchanged, in which the Reuters reporter described the digital materials from Islamic extremists that were shown at the congressional hearing. During the segment that apparently most captured the attention of the wire service reporters, eerie music played as an English-speaking narrator condemned the “infidel” and declared that he had “put a jihad” on them, as aerial shots moved over 3D computer-generated images of flaming oil facilities and mosques covered with geometric designs. Suddenly, this menacing voice-over was interrupted by an explosion, as a virtual rocket was launched into a simulated military helicopter. The Reuters reporter shared this dystopian vision from cyberspace with Western audiences by quoting directly from the chilling commentary and describing a dissonant montage of images and remixed sound. “I was just a boy when the infidels came to my village in Blackhawk helicopters,” a narrator’s voice said as the screen flashed between images of street-level gunfights, explosions and helicopter assaults. Then came a recording of President George W. Bush’s September 16, 2001, statement: “This crusade, this war on terrorism, is going to take a while.” It was edited to repeat the word “crusade,” which Muslims often define as an attack on Islam by Christianity. According to the news reports, the key piece of evidence before Congress seemed to be a film by “SonicJihad” of recorded videogame play, which – according to the experts – was widely distributed online. Much of the clip takes place from the point of view of a first-person shooter, seen as if through the eyes of an armed insurgent, but the viewer also periodically sees third-person action in which the player appears as a running figure wearing a red-and-white checked keffiyeh, who dashes toward the screen with a rocket launcher balanced on his shoulder. Significantly, another of the player’s hand-held weapons is a detonator that triggers remote blasts. As jaunty music plays, helicopters, tanks, and armoured vehicles burst into smoke and flame. Finally, at the triumphant ending of the video, a green and white flag bearing a crescent is hoisted aloft into the sky to signify victory by Islamic forces. To explain the existence of this digital alternative history in which jihadists could be conquerors, the Reuters story described the deviousness of the country’s terrorist opponents, who were now apparently modifying popular videogames through their wizardry and inserting anti-American, pro-insurgency content into U.S.-made consumer technology. One of the latest video games modified by militants is the popular “Battlefield 2” from leading video game publisher, Electronic Arts Inc of Redwood City, California. Jeff Brown, a spokesman for Electronic Arts, said enthusiasts often write software modifications, known as “mods,” to video games. “Millions of people create mods on games around the world,” he said. “We have absolutely no control over them. It’s like drawing a mustache on a picture.” Although the Electronic Arts executive dismissed the activities of modders as a “mustache on a picture” that could only be considered little more than childish vandalism of their off-the-shelf corporate product, others saw a more serious form of criminality at work. Testifying experts and the legislators listening on the committee used the video to call for greater Internet surveillance efforts and electronic counter-measures. Within twenty-four hours of the sensationalistic news breaking, however, a group of Battlefield 2 fans was crowing about the idiocy of reporters. The game play footage wasn’t from a high-tech modification of the software by Islamic extremists; it had been posted on a Planet Battlefield forum the previous December of 2005 by a game fan who had cut together regular game play with a Bush remix and a parody snippet of the soundtrack from the 2004 hit comedy film Team America. The voice describing the Black Hawk helicopters was the voice of Trey Parker of South Park cartoon fame, and – much to Parker’s amusement – even the mention of “goats screaming” did not clue spectators in to the fact of a comic source. Ironically, the moment in the movie from which the sound clip is excerpted is one about intelligence gathering. As an agent of Team America, a fictional elite U.S. commando squad, the hero of the film’s all-puppet cast, Gary Johnston, is impersonating a jihadist radical inside a hostile Egyptian tavern that is modelled on the cantina scene from Star Wars. Additional laughs come from the fact that agent Johnston is accepted by the menacing terrorist cell as “Hakmed,” despite the fact that he utters a series of improbable clichés made up of incoherent stereotypes about life in the Middle East while dressed up in a disguise made up of shoe polish and a turban from a bathroom towel. The man behind the “SonicJihad” pseudonym turned out to be a twenty-five-year-old hospital administrator named Samir, and what reporters and representatives saw was nothing more exotic than game play from an add-on expansion pack of Battlefield 2, which – like other versions of the game – allows first-person shooter play from the position of the opponent as a standard feature. While SonicJihad initially joined his fellow gamers in ridiculing the mainstream media, he also expressed astonishment and outrage about a larger politics of reception. In one interview he argued that the media illiteracy of Reuters potentially enabled a whole series of category errors, in which harmless gamers could be demonised as terrorists. It wasn’t intended for the purpose what it was portrayed to be by the media. So no I don’t regret making a funny video . . . why should I? The only thing I regret is thinking that news from Reuters was objective and always right. The least they could do is some online research before publishing this. If they label me al-Qaeda just for making this silly video, that makes you think, what is this al-Qaeda? And is everything al-Qaeda? Although Sonic Jihad dismissed his own work as “silly” or “funny,” he expected considerably more from a credible news agency like Reuters: “objective” reporting, “online research,” and fact-checking before “publishing.” Within the week, almost all of the salient details in the Reuters story were revealed to be incorrect. SonicJihad’s film was not made by terrorists or for terrorists: it was not created by “Islamic militants” for “Muslim youths.” The videogame it depicted had not been modified by a “tech-savvy militant” with advanced programming skills. Of course, what is most extraordinary about this story isn’t just that Reuters merely got its facts wrong; it is that a self-identified “parody” video was shown to the august House Intelligence Committee by a team of well-paid “experts” from the Science Applications International Corporation (SAIC), a major contractor with the federal government, as key evidence of terrorist recruitment techniques and abuse of digital networks. Moreover, this story of media illiteracy unfolded in the context of a fundamental Constitutional debate about domestic surveillance via communications technology and the further regulation of digital content by lawmakers. Furthermore, the transcripts of the actual hearing showed that much more than simple gullibility or technological ignorance was in play. Based on their exchanges in the public record, elected representatives and government experts appear to be keenly aware that the digital discourses of an emerging information culture might be challenging their authority and that of the longstanding institutions of knowledge and power with which they are affiliated. These hearings can be seen as representative of a larger historical moment in which emphatic declarations about prohibiting specific practices in digital culture have come to occupy a prominent place at the podium, news desk, or official Web portal. This environment of cultural reaction can be used to explain why policy makers’ reaction to terrorists’ use of networked communication and digital media actually tells us more about our own American ideologies about technology and rhetoric in a contemporary information environment. When the experts come forward at the Sonic Jihad hearing to “walk us through the media and some of the products,” they present digital artefacts of an information economy that mirrors many of the features of our own consumption of objects of electronic discourse, which seem dangerously easy to copy and distribute and thus also create confusion about their intended meanings, audiences, and purposes. From this one hearing we can see how the reception of many new digital genres plays out in the public sphere of legislative discourse. Web pages, videogames, and Weblogs are mentioned specifically in the transcript. The main architecture of the witnesses’ presentation to the committee is organised according to the rhetorical conventions of a PowerPoint presentation. Moreover, the arguments made by expert witnesses about the relationship of orality to literacy or of public to private communications in new media are highly relevant to how we might understand other important digital genres, such as electronic mail or text messaging. The hearing also invites consideration of privacy, intellectual property, and digital “rights,” because moral values about freedom and ownership are alluded to by many of the elected representatives present, albeit often through the looking glass of user behaviours imagined as radically Other. For example, terrorists are described as “modders” and “hackers” who subvert those who properly create, own, legitimate, and regulate intellectual property. To explain embarrassing leaks of infinitely replicable digital files, witness Ron Roughead says, “We’re not even sure that they don’t even hack into the kinds of spaces that hold photographs in order to get pictures that our forces have taken.” Another witness, Undersecretary of Defense for Policy and International Affairs, Peter Rodman claims that “any video game that comes out, as soon as the code is released, they will modify it and change the game for their needs.” Thus, the implication of these witnesses’ testimony is that the release of code into the public domain can contribute to political subversion, much as covert intrusion into computer networks by stealthy hackers can. However, the witnesses from the Pentagon and from the government contractor SAIC often present a contradictory image of the supposed terrorists in the hearing transcripts. Sometimes the enemy is depicted as an organisation of technological masterminds, capable of manipulating the computer code of unwitting Americans and snatching their rightful intellectual property away; sometimes those from the opposing forces are depicted as pre-modern and even sub-literate political innocents. In contrast, the congressional representatives seem to focus on similarities when comparing the work of “terrorists” to the everyday digital practices of their constituents and even of themselves. According to the transcripts of this open hearing, legislators on both sides of the aisle express anxiety about domestic patterns of Internet reception. Even the legislators’ own Web pages are potentially disruptive electronic artefacts, particularly when the demands of digital labour interfere with their duties as lawmakers. Although the subject of the hearing is ostensibly terrorist Websites, Representative Anna Eshoo (D-California) bemoans the difficulty of maintaining her own official congressional site. As she observes, “So we are – as members, I think we’re very sensitive about what’s on our Website, and if I retained what I had on my Website three years ago, I’d be out of business. So we know that they have to be renewed. They go up, they go down, they’re rebuilt, they’re – you know, the message is targeted to the future.” In their questions, lawmakers identify Weblogs (blogs) as a particular area of concern as a destabilising alternative to authoritative print sources of information from established institutions. Representative Alcee Hastings (D-Florida) compares the polluting power of insurgent bloggers to that of influential online muckrakers from the American political Right. Hastings complains of “garbage on our regular mainstream news that comes from blog sites.” Representative Heather Wilson (R-New Mexico) attempts to project a media-savvy persona by bringing up the “phenomenon of blogging” in conjunction with her questions about jihadist Websites in which she notes how Internet traffic can be magnified by cooperative ventures among groups of ideologically like-minded content-providers: “These Websites, and particularly the most active ones, are they cross-linked? And do they have kind of hot links to your other favorite sites on them?” At one point Representative Wilson asks witness Rodman if he knows “of your 100 hottest sites where the Webmasters are educated? What nationality they are? Where they’re getting their money from?” In her questions, Wilson implicitly acknowledges that Web work reflects influences from pedagogical communities, economic networks of the exchange of capital, and even potentially the specific ideologies of nation-states. It is perhaps indicative of the government contractors’ anachronistic worldview that the witness is unable to answer Wilson’s question. He explains that his agency focuses on the physical location of the server or ISP rather than the social backgrounds of the individuals who might be manufacturing objectionable digital texts. The premise behind the contractors’ working method – surveilling the technical apparatus not the social network – may be related to other beliefs expressed by government witnesses, such as the supposition that jihadist Websites are collectively produced and spontaneously emerge from the indigenous, traditional, tribal culture, instead of assuming that Iraqi insurgents have analogous beliefs, practices, and technological awareness to those in first-world countries. The residual subtexts in the witnesses’ conjectures about competing cultures of orality and literacy may tell us something about a reactionary rhetoric around videogames and digital culture more generally. According to the experts before Congress, the Middle Eastern audience for these videogames and Websites is limited by its membership in a pre-literate society that is only capable of abortive cultural production without access to knowledge that is archived in printed codices. Sometimes the witnesses before Congress seem to be unintentionally channelling the ideas of the late literacy theorist Walter Ong about the “secondary orality” associated with talky electronic media such as television, radio, audio recording, or telephone communication. Later followers of Ong extend this concept of secondary orality to hypertext, hypermedia, e-mail, and blogs, because they similarly share features of both speech and written discourse. Although Ong’s disciples celebrate this vibrant reconnection to a mythic, communal past of what Kathleen Welch calls “electric rhetoric,” the defence industry consultants express their profound state of alarm at the potentially dangerous and subversive character of this hybrid form of communication. The concept of an “oral tradition” is first introduced by the expert witnesses in the context of modern marketing and product distribution: “The Internet is used for a variety of things – command and control,” one witness states. “One of the things that’s missed frequently is how and – how effective the adversary is at using the Internet to distribute product. They’re using that distribution network as a modern form of oral tradition, if you will.” Thus, although the Internet can be deployed for hierarchical “command and control” activities, it also functions as a highly efficient peer-to-peer distributed network for disseminating the commodity of information. Throughout the hearings, the witnesses imply that unregulated lateral communication among social actors who are not authorised to speak for nation-states or to produce legitimated expert discourses is potentially destabilising to political order. Witness Eric Michael describes the “oral tradition” and the conventions of communal life in the Middle East to emphasise the primacy of speech in the collective discursive practices of this alien population: “I’d like to point your attention to the media types and the fact that the oral tradition is listed as most important. The other media listed support that. And the significance of the oral tradition is more than just – it’s the medium by which, once it comes off the Internet, it is transferred.” The experts go on to claim that this “oral tradition” can contaminate other media because it functions as “rumor,” the traditional bane of the stately discourse of military leaders since the classical era. The oral tradition now also has an aspect of rumor. A[n] event takes place. There is an explosion in a city. Rumor is that the United States Air Force dropped a bomb and is doing indiscriminate killing. This ends up being discussed on the street. It ends up showing up in a Friday sermon in a mosque or in another religious institution. It then gets recycled into written materials. Media picks up the story and broadcasts it, at which point it’s now a fact. In this particular case that we were telling you about, it showed up on a network television, and their propaganda continues to go back to this false initial report on network television and continue to reiterate that it’s a fact, even though the United States government has proven that it was not a fact, even though the network has since recanted the broadcast. In this example, many-to-many discussion on the “street” is formalised into a one-to many “sermon” and then further stylised using technology in a one-to-many broadcast on “network television” in which “propaganda” that is “false” can no longer be disputed. This “oral tradition” is like digital media, because elements of discourse can be infinitely copied or “recycled,” and it is designed to “reiterate” content. In this hearing, the word “rhetoric” is associated with destructive counter-cultural forces by the witnesses who reiterate cultural truisms dating back to Plato and the Gorgias. For example, witness Eric Michael initially presents “rhetoric” as the use of culturally specific and hence untranslatable figures of speech, but he quickly moves to an outright castigation of the entire communicative mode. “Rhetoric,” he tells us, is designed to “distort the truth,” because it is a “selective” assembly or a “distortion.” Rhetoric is also at odds with reason, because it appeals to “emotion” and a romanticised Weltanschauung oriented around discourses of “struggle.” The film by SonicJihad is chosen as the final clip by the witnesses before Congress, because it allegedly combines many different types of emotional appeal, and thus it conveniently ties together all of the themes that the witnesses present to the legislators about unreliable oral or rhetorical sources in the Middle East: And there you see how all these products are linked together. And you can see where the games are set to psychologically condition you to go kill coalition forces. You can see how they use humor. You can see how the entire campaign is carefully crafted to first evoke an emotion and then to evoke a response and to direct that response in the direction that they want. Jihadist digital products, especially videogames, are effective means of manipulation, the witnesses argue, because they employ multiple channels of persuasion and carefully sequenced and integrated subliminal messages. To understand the larger cultural conversation of the hearing, it is important to keep in mind that the related argument that “games” can “psychologically condition” players to be predisposed to violence is one that was important in other congressional hearings of the period, as well one that played a role in bills and resolutions that were passed by the full body of the legislative branch. In the witness’s testimony an appeal to anti-game sympathies at home is combined with a critique of a closed anti-democratic system abroad in which the circuits of rhetorical production and their composite metonymic chains are described as those that command specific, unvarying, robotic responses. This sharp criticism of the artful use of a presentation style that is “crafted” is ironic, given that the witnesses’ “compilation” of jihadist digital material is staged in the form of a carefully structured PowerPoint presentation, one that is paced to a well-rehearsed rhythm of “slide, please” or “next slide” in the transcript. The transcript also reveals that the members of the House Intelligence Committee were not the original audience for the witnesses’ PowerPoint presentation. Rather, when it was first created by SAIC, this “expert” presentation was designed for training purposes for the troops on the ground, who would be facing the challenges of deployment in hostile terrain. According to the witnesses, having the slide show showcased before Congress was something of an afterthought. Nonetheless, Congressman Tiahrt (R-KN) is so impressed with the rhetorical mastery of the consultants that he tries to appropriate it. As Tiarht puts it, “I’d like to get a copy of that slide sometime.” From the hearing we also learn that the terrorists’ Websites are threatening precisely because they manifest a polymorphously perverse geometry of expansion. For example, one SAIC witness before the House Committee compares the replication and elaboration of digital material online to a “spiderweb.” Like Representative Eshoo’s site, he also notes that the terrorists’ sites go “up” and “down,” but the consultant is left to speculate about whether or not there is any “central coordination” to serve as an organising principle and to explain the persistence and consistency of messages despite the apparent lack of a single authorial ethos to offer a stable, humanised, point of reference. In the hearing, the oft-cited solution to the problem created by the hybridity and iterability of digital rhetoric appears to be “public diplomacy.” Both consultants and lawmakers seem to agree that the damaging messages of the insurgents must be countered with U.S. sanctioned information, and thus the phrase “public diplomacy” appears in the hearing seven times. However, witness Roughhead complains that the protean “oral tradition” and what Henry Jenkins has called the “transmedia” character of digital culture, which often crosses several platforms of traditional print, projection, or broadcast media, stymies their best rhetorical efforts: “I think the point that we’ve tried to make in the briefing is that wherever there’s Internet availability at all, they can then download these – these programs and put them onto compact discs, DVDs, or post them into posters, and provide them to a greater range of people in the oral tradition that they’ve grown up in. And so they only need a few Internet sites in order to distribute and disseminate the message.” Of course, to maintain their share of the government market, the Science Applications International Corporation also employs practices of publicity and promotion through the Internet and digital media. They use HTML Web pages for these purposes, as well as PowerPoint presentations and online video. The rhetoric of the Website of SAIC emphasises their motto “From Science to Solutions.” After a short Flash film about how SAIC scientists and engineers solve “complex technical problems,” the visitor is taken to the home page of the firm that re-emphasises their central message about expertise. The maps, uniforms, and specialised tools and equipment that are depicted in these opening Web pages reinforce an ethos of professional specialisation that is able to respond to multiple threats posed by the “global war on terror.” By 26 June 2006, the incident finally was being described as a “Pentagon Snafu” by ABC News. From the opening of reporter Jake Tapper’s investigative Webcast, established government institutions were put on the spot: “So, how much does the Pentagon know about videogames? Well, when it came to a recent appearance before Congress, apparently not enough.” Indeed, the very language about “experts” that was highlighted in the earlier coverage is repeated by Tapper in mockery, with the significant exception of “independent expert” Ian Bogost of the Georgia Institute of Technology. If the Pentagon and SAIC deride the legitimacy of rhetoric as a cultural practice, Bogost occupies himself with its defence. In his recent book Persuasive Games: The Expressive Power of Videogames, Bogost draws upon the authority of the “2,500 year history of rhetoric” to argue that videogames represent a significant development in that cultural narrative. Given that Bogost and his Watercooler Games Weblog co-editor Gonzalo Frasca were actively involved in the detective work that exposed the depth of professional incompetence involved in the government’s line-up of witnesses, it is appropriate that Bogost is given the final words in the ABC exposé. As Bogost says, “We should be deeply bothered by this. We should really be questioning the kind of advice that Congress is getting.” Bogost may be right that Congress received terrible counsel on that day, but a close reading of the transcript reveals that elected officials were much more than passive listeners: in fact they were lively participants in a cultural conversation about regulating digital media. After looking at the actual language of these exchanges, it seems that the persuasiveness of the misinformation from the Pentagon and SAIC had as much to do with lawmakers’ preconceived anxieties about practices of computer-mediated communication close to home as it did with the contradictory stereotypes that were presented to them about Internet practices abroad. In other words, lawmakers found themselves looking into a fun house mirror that distorted what should have been familiar artefacts of American popular culture because it was precisely what they wanted to see. 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Morgan, David. “Islamists Using U.S. Video Games in Youth Appeal.” Reuters online news service. 4 May 2006 http://today.reuters.com/news/ArticleNews.aspx?type=topNews &storyID=2006-05-04T215543Z_01_N04305973_RTRUKOC_0_US-SECURITY- VIDEOGAMES.xml&pageNumber=0&imageid=&cap=&sz=13&WTModLoc= NewsArt-C1-ArticlePage2>. Ong, Walter J. Orality and Literacy: The Technologizing of the Word. London/New York: Methuen, 1982. Parker, Trey. Online posting. 7 May 2006. 9 May 2006 http://www.treyparker.com>. Plato. “Gorgias.” Plato: Collected Dialogues. Princeton: Princeton UP, 1961. Shrader, Katherine. “Pentagon Surfing Thousands of Jihad Sites.” Associated Press 4 May 2006. SonicJihad. “SonicJihad: A Day in the Life of a Resistance Fighter.” Online posting. 26 Dec. 2005. Planet Battlefield Forums. 9 May 2006 http://www.forumplanet.com/planetbattlefield/topic.asp?fid=13670&tid=1806909&p=1>. Tapper, Jake, and Audery Taylor. “Terrorist Video Game or Pentagon Snafu?” ABC News Nightline 21 June 2006. 30 June 2006 http://abcnews.go.com/Nightline/Technology/story?id=2105128&page=1>. U.S. Congressional Record. Panel I of the Hearing of the House Select Intelligence Committee, Subject: “Terrorist Use of the Internet for Communications.” Federal News Service. 4 May 2006. Welch, Kathleen E. Electric Rhetoric: Classical Rhetoric, Oralism, and the New Literacy. Cambridge, MA: MIT Press, 1999. 
 
 
 
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 Losh, Elizabeth. "Artificial Intelligence: Media Illiteracy and the SonicJihad Debacle in Congress." M/C Journal 10.5 (2007). echo date('d M. Y'); ?> <http://journal.media-culture.org.au/0710/08-losh.php>. APA Style
 Losh, E. (Oct. 2007) "Artificial Intelligence: Media Illiteracy and the SonicJihad Debacle in Congress," M/C Journal, 10(5). Retrieved echo date('d M. Y'); ?> from <http://journal.media-culture.org.au/0710/08-losh.php>.