Dissertations / Theses on the topic 'Free-form lens'

Le paf (1-o-alkyl-2-acetyl-sn-glycero-3-phosphorylcholine) est aujourd'hui reconnu comme un des plus importants neuromediateurs lipidiques. Dans ce travail, nous montrons une action du paf sur les cellules de la lignee de neuroblastome n1e-115. Par les techniques de liaison, nous avons mis en evidence sur ces cellules la presence de deux types de recepteurs du paf. L'activation de ces recepteurs par des concentrations physiologiques de paf produit une accumulation d'inositol triphosphate, et une augmentation rapide et transitoire du calcium libre cytosolique. Cette augmentation du calcium libre cytosolique fait intervenir a la fois une redistribution du calcium intracellulaire et des influx de calcium externe. Ces influx de calcium passent essentiellement via des canaux permeables aux ions ca#2#+ de type receptor-operated channel. Nous montrons la presence, sur ces cellules, de canaux permeables au ca#2#+ et activables par la thapsigargine correspondant tres probablement a des canaux calciques activables via la depletion des reserves intracellulaires. Ces canaux interviennent dans la reponse induite par le paf. A l'aide de la technique de voltage impose sur cellule entiere, nous avons mis en evidence une activation possible par le paf des canaux calciques sensibles au voltage de type l. Cependant, cette derniere action du paf ne participe que, de facon minime, aux entrees de ca#2#+. L'activation de ces canaux est, en effet, bloquee par une hyperpolarisation transitoire en reponse a l'activation par le paf de canaux potassiques du type bk(ca). Cette derniere action du paf est la consequence de la seule augmentation du calcium libre cytosolique, et ne resulte pas d'une action directe du paf sur ces bk(ca). Enfin, a l'aide de la technique du patch-clamp, nous n'avons pas mis en evidence l'effet du paf sur les autres permeabilites ioniques membranaires de ces cellules (courants na#+ et k#+ sensibles au potentiel)

碩士
國立虎尾科技大學
機械與電腦輔助工程系碩士班
105
A free-form (FF) surface design method is proposed for a general axial-symmetrical collimator system consisting of a light source and a TIR lens with two coupled FF boundary surfaces. The profiles of the boundary surfaces are designed using a FF surface construction method such that each incident ray is directed (refracted and reflected) in such a way as to form a specified image pattern on the target plane. The light ray paths within the system are analyzed using an exact analytical model and a skew-ray tracing approach. In addition, the validity of the proposed FF design method is demonstrated by means of ZEMAX simulations. It is shown that the illumination distribution formed on the target plane is in good agreement with that specified by the user. The proposed surface construction method is mathematically straightforward and easily implemented in computer code. As such, it provides a useful tool for the design and analysis of general axial symmetrical optical systems.

碩士
國立臺灣科技大學
電子工程系
102
Electrical lighting consumes around 1/3 of the total electricity, it depletes rapidly the limited fosil energy sources used to generate electricity. Daylighting systems therefore become one of the most popular research issues recently. Among various daylighting systems, one is the well-known HIMAWARI, designed by a team from Japan. The system is highly efficient and provides sufficient light for indoor illumination. However, such systems are dynamic systems, which need additional electricity to drive the suntracker for gathering sunlight. Comparing with the static systems, in which the tolerance angle of the light collectors are usually designed larger rather than with the suntrackor of the HIMAWALI. Among on these static systems, the Natural Light Illumination System (NLIS) is an innovative static system, using rectangular prisms structure to compress and transmit the sunlight indoor for illumination . There are many advantages of NLIS like cascadable and modulized that is easier for installation and maintenance the system. The NLIS system is composed of three sub-systems, light collection, light transmission, and light emission. The overall efficiency of the NLIS is the sum of the three subsystems. Since this paper is mainly focus on the reaearch between the light collection subsystem and the transmission subsystem. We mainly explore the way to enhance the efficiency of the light transmission subsystem. Regarding to the transmission subsystem, there are two often-used component, the light pipe and the optical fiber. The light pipe is composed of tubes and lenses. With the properties of focusing and divergence, the lenses in the light pipe allow the light be transmitted to a large distance without substantial loss. Due to the cost of the fiber is too high for long distance to transmit, the light transmission component we choose to study is the light pipe. The research shows that the numerical aperture of the lightpipe is ±〖10〗^° and the angles behind the collection module are larger than〖 10〗^°. It would cause low efficiency and lead to insufficient light for indoor illumination. To solve this problem, we design a collimating lens based on free-form method to be a light coupler between the collection subsystem and the light transmission subsystem. The free-form lens is made of BK7 glass. When the light passing through the lens, the light will be converged according to the shape of the lens. The surface is constructed based on parting the light source into cells and calculateing the tangent vector of the refractive surface on the basis of the light distribution on each cells. Finally, we connect each free-form lens together to form the complete free-form lens and the light passing through the lens are converged as nearly parallel light. With the nearly parallel light, the efficiency of transmission part can be greatly enhanced.

碩士
國立中央大學
光電科學與工程學系
103
In this thesis, we built two types of initial model of free-form surface secondary optical system, lens and reflector based on principles of geometry optics. Then use 2D/3D interactive optimizer of TracePro to create initial model, and automatic optimization of free-form surfaces. The beam angle (50% lv) of the secondary optical system on 300mm diameter surface light source is 9 degrees or less. Apply this method, we avoiding repeated re-set parameters and adjust model, significantly reducing the time it takes. Finally we got the best model of high precision free-form surface secondary optical element in a shorter time.

碩士
國立成功大學
物理學系碩博士班
98
Light Emitting Diode (LED) possesses several advantages, having high energy-transferring efficiency, long life and small physical size. As a result, Light Emitting Diodes (LED) should become a general light source in human life in a few years. For example, it can be used to indoor lighting and Liquid crystal display (LCD) backlight module. In this thesis, we design several free-form lenses which can produce uniform angular intensity distribution or uniform illuminance. In this thesis, we find an ordinary differential equation (ODE) describing the of free-form lens surface by using the concept of energy conservation and geometrical optics. We then calculate the free-form lens surface by solving the ODE. The free-form lens properties are verified by ray-tracing simulation package, LightTools. The purposes of these free-form lenses are increasing light-using efficiency, decreasing the light source cost and energy-saving.

碩士
明道大學
光電暨能源工程學系碩士班
98
The purpose of this study is to design a free-form surface LED-based headlamp lens, which satisfied ECE R112 low-beam shape and illuminance legal requirement. The design procedure is to use two high-power LED sources, which is the type of OSRAM LE-UW-E3B LED ( 18w / 610lm ) , and to set up a free-from lens as a basic beam projector and then to use Light Tools software to simulate and optimize the required specification performance. The total optical efficiency can reach up to 80 %. The thesis contains the design process, the performance evaluation, the measurement method, and the tolerance analysis of source position errors, which shows that the tolerance of the source position error can be ±0.3 mm for up and down cases, and 0.2 mm for backward moving.

碩士
國立中央大學
光電科學與工程學系
104
When applied outdoors, LEDs give a Lambertian distribution of luminance which can result in a harsh divergence of brightness. In order to prevent the heterogeneous luminance patterns and minimize the light pollution whilst maintaining the quality of roadway lighting, software TracePro is incorporated in this study to create an initial model of asymmetrical secondary optical lens. Since the objective of this research is to comply with “the regulations of LED street light technology in Taiwan”, the built-in optimizer of the software is utilized to maximize the ratio of pole distance/pole height to 1:4.5. An overall evaluation of this lighting design with software Dialux indicates that the average of illumination is above 15lux and the uniformity is above 0.33 which meet the standard requirements of roadway lighting.

碩士
國立臺灣科技大學
電子工程系
104
Nowadays, global warming has become a major issue. Reducing the consumption of fossil fuel and saving energy were the top priorities. In response to the energy crisis, renewable energy has been widely taken as other energy options. Solar energy is one of the most essential and abundant energy. If we can collect and transmit natural light into buildings without opto-electronic conversion, that will save energy and provide healthier light into our daily life. Therefore, our team designed a series of products known as Natural Light Illumination System (NLIS). In developing the high-quality NLIS, our primary concern was to increase the efficiency of the system. When the concentrators in daylight system collects sunlight, the light transmits through light pipe or fiber to any room you want. However, the efficiency decreases dramatically as the number of concentrator increases, due to the interconnection parts which encounter huge loss. In this paper, we present a free-form collimator applied to the outputs of LightBricks. The collimator is composed of different microlenses, which are derived from geometric optics, and include free-form refractive surfaces and total internal reflective surfaces. By mesh generation method, we successfully compress the collimator’s volume and the computer simulation results show that a ratio of luminous flux within ±25° and the total flux within ±90° on the collimator's output has a dramatically decrease, and the collimator with the best performance has a ratio of luminous flux within ±1° and the total flux within ±90° at 79%. Also it has an optical efficiency of 64%.

碩士
國立交通大學
顯示科技研究所
99
Traditional mechanistic input device of human machine interface is widely used in life. Since the mechanism has a limit size for user controlling, the system size can’t be reduced effectively. The wastage also is high when it’s used frequently. But the optical device, a new kind of device, is compact, sensitive and durable than mechanical one. Therefore, the optical input device is popular and everywhere now. In this thesis, we provided a simple optical device that is compact and useful for mobile device. We offer a touch optical input device; it captures the information from the surface of contacting object or skin. The information will be transferred to electric signal for controlling the device. The device combines two free-form lens, which the free-from lens can fold the optical axis and, therefore, the system size will be reduced. Compact system and touch control is fit to mobile device application. We will show a complete design flow in this thesis. First, we use paraxial optics to do an approximation computing for this image system. Then the optical design software helps us to modify and optimize the system. Finally, we also use the software to analysis the preliminary tolerance of this design. This step offers a concept of the accuracy on manufacture of this design. According to the tolerance analysis, this design needs high accuracy on some parts; hence the manufacturing threshold is higher. But it’s a possible design on realize.

碩士
明道大學
光電暨能源工程學系碩士班
100
The purpose of this study is to design a free-form surface LED-based headlamp lens, which satisfied “ECE R112 low-beam shape” and illuminance legal requirement. The design is mainly focused on the LED secondary optical design, which covers the refraction, reflection and total internal reflection in-side the singlet lens. The thesis also addressed how the free-form surface is used in this headlamp lens design. Use only a 10-watt 1050 lumen high-power LED. After the Light Tools software simulation, the design has reached the ECE-R112 legal reguirements. The overall optical efficiently is 60%. Finally the lens has been tested which show the performance has matched the light patent only remove some unwanted light at zone Ⅲneed to be removed.

碩士
高苑科技大學
電子工程研究所
101
In this paper design a U-type 2X zoom projector lens design with two prisms will have less overall length than a general optical design; however, with the zigzag path of light , aberrations Contain : spherical aberration, coma aberration, distortion, and Image Plan Offset will result. In such a design, a free-form surface prism with aspherical coefficients may significantly improve the system’s performance if the coefficients of the free-form surface prisms are well optimized. Use Taguchi Method is employed in this study to analysis Spherical Aberration and Coma Aberration , get best Control factor purpose, then with the configuration of the level reached a multi-objective optimization design purposes, in other words, this study is the Hybrid Taguchi-Fuzzy Method, to identify the best parameters of free-form surface design can effectively reduce the generation of spherical aberration and coma aberration. In this paper the best results, spherical aberration and coma were reduced 1.12% and 0.83%.

碩士
國立臺灣科技大學
光電工程研究所
107
Traditional tunnel lighting has the problem of poor lighting environment and huge energy consumption. In this study, two different lenses were designed with natural light and LED as the light source. When the sunlight is enough, the natural light illumination system is used to give tunnel illumination in the threshold zone and the exit zone to reduce the LED usage. When the sunlight is not enough, the LED can complement the tunnel lighting. In terms of the two designs, the linear Fresnel lens is established as a light-emitting element of a natural light illumination system with a microstructure, and the free-form surface asymmetric lens of the LED is established by the catadioptric method. The two lenses are verified by the optical simulation software FRED. The uniformity on the road surface can reach about 84.8 and 80.2, and the efficiency are about 78.3% and 84.8% respectively. The model of the Hsueh-Shan tunnel was established by DIALux, and the two kinds of lenses were simulated in the tunnel in three modes. The mode 1 is only used with linear Fresnel lens when sunlight is enough. The mode 2 is only LED lighting when there is no sunlight. The mode 3 is hybrid lighting with the two kinds sources at the same time, which can adjust the lighting ratio of LED according to the intensity of natural light to save energy. As a result, the three modes can meet the first section is greater than 120cd/m2, the second section is greater than 60cd/m2 in the threshold zone and the first section is greater than 30cd/m2, the second section is greater than 15cd/m2 in the exit zone, the total uniformity U0 is greater than or equal to 0.4, longitudinal uniformity U1 is greater than or equal to 0.6. Finally, this study solves three problems. First, uses LED as the light source, and uses optical design to improve the problem that the traditional high-pressure sodium lamp itself is too high to causes glare. Second, the average illuminance method is used to calculate the most appropriate lamp spacing and reduce the zebra pattern on the road surface. Third, combines the natural light and the artificial light source, when the outdoor luminance is the highest, the natural light replaces the traditional tunnel light to be fully open. When the natural light energy is reduced, the LED is used to supplement the tunnel lighting to maintain the tunnel lighting environment. The tunnel lights do not need to operate 24 hours a day to save energy.

碩士
國立中山大學
機械與機電工程學系研究所
103
Traditional surgical shadowless lamps are generally designed as projection type with many light bulbs as light source, but this kind of structures will not only occur mercury pollution but also heat radiation that increase the temperature on the target plane. An additional filter that will absorb the energy of light is necessary to block the radiation. In this thesis, LED (Light-Emitting Diode) is applied to replace the halogen lamp, and two different methods of designing surgical shadowless lamp are present, that is based on elliptical equation. A freeform uniform lens is designed to fix the problem of Lambertian distribution of LED, that prove the uniformity on the target plane. Besides, thin film metallic glass (TFMG), is applied as the material of reflective layer. TFMG have great mechanical properties that can extend the life term of lamp and the Ag-based TFMG is anti-bacterial. According to the result of simulation, the most outstanding model is the one with 3 elliptical curves designed by un-coaxial method, which central illuminance is 141,7801lux, and the d50/d10 is 60.8%, 36cm in depth of working. The shadow dilution with one/double masks are 63.6% and 57.1%, while 59.6% and 61% in a tube with one/double masks. After combination with freeform uniform intensity lens, central illuminance lightly decrease to 130,140lux, which is because the absorption of lens material. But d50/d10 have increased to 65% and the shadowless dilution with one/double masks are 65.7% and 53.6%, while 61.8% and 58.7% in a tube with one/double masks. And the depth of working is 36.5cm. Computer numerical control milling machine was used to fabricate the actual surgical shadowless lamp, illuminometer and spectrum were applied to measure the emission result. According to the measurement result, Ec is 110,500lux with 59.9% in d50/d10, shadow dilution with single/double masks are 58.96% and 56.16%, respectively, and 57.46% and 58.03% with a tube. The working depth is 32.8cm.

碩士
高苑科技大學
電子工程研究所
101
With the trend of volume minimization, some of methods to improve the traditional zoom lens gradually raised, such as Liquid Lens and free-form surfaces. In the optical design,when the light passes through the optical system, the system path is zigzag and complex, so we can find some aberration from imaging surface. These aberrations include 1. Spherical aberration 2. Coma aberration 3. Distortion aberrations. We need free-form surface prism design by means of revise aberration.In this paper a U-type 2X zoom of free-form surfaces projector lens design with twoprisms will have less overall length than a general optical design , and use the Taguchi method were analyzed lens parameter optimization of Spherical Aberration and Coma Aberration by analysis of the optimal control parameters, and optimum level , the design of the type of the prism free-form surfaces polynomial order, finally hybrid Taguchi-RMCO(Robust Multiple Criterion Optimization) the best lens configuration combinations.The purpose of this study using hybrid Taguchi method - robust multi-objective optimization ways to improve its spherical aberration, coma aberration.To improve the efficiency, the ninth group is the best of this experimental group, spherical aberration improved 0.15%, while the coma is improved 0.33%.

Theoretical and numerical modeling of optical systems are increasingly being utilized in a wide range of areas in physics and engineering for characterizing and improving existing systems or developing new methods. This dissertation focuses on determining and improving the performance of imaging and non-imaging optical systems through modeling and developing model-aware enhancement methods. We evaluate the performance, demonstrate enhancements in terms of resolution and light collection efficiency, and improve the capabilities of the systems through changes to the system design and through post-processing techniques. We consider application areas in integrated circuit (IC) imaging for fault analysis and malicious circuitry detection, and free-form lens design for creating prescribed illumination patterns. The first part of this dissertation focuses on sub-surface imaging of ICs for fault analysis using a solid immersion lens (SIL) microscope. We first derive the Green's function of the microscope and use it to determine its resolution limits for bulk silicon and silicon-on-insulator (SOI) chips. We then propose an optimization framework for designing super-resolving apodization masks that utilizes the developed model and demonstrate the trade-offs in designing such masks. Finally, we derive the full electromagnetic model of the SIL microscope that models the image of an arbitrary sub-surface structure. With the rapidly shrinking dimensions of ICs, we are increasingly limited in resolving the features and identifying potential modifications despite the resolution improvements provided by the state-of-the-art microscopy techniques and enhancement methods described here. In the second part of this dissertation, we shift our focus away from improving the resolution and consider an optical framework that does not require high resolution imaging for detecting malicious circuitry. We develop a classification-based high-throughput gate identification method that utilizes the physical model of the optical system. We then propose a lower-throughput system to increase the detection accuracy, based on higher resolution imaging to supplement the former method. Finally, we consider the problem of free-form lens design for forming prescribed illumination patterns as a non-imaging application. Common methods that design free-form lenses for forming patterns consider the input light source to be a point source, however using extended light sources with such lenses lead to significant blurring in the resulting pattern. We propose a deconvolution-based framework that utilizes the lens geometry to model the blurring effects and eliminates this degradation, resulting in sharper patterns.

碩士
國立虎尾科技大學
電機工程研究所
103
The crystalline lens focus will slowly degenerate with the growth of age, and produce presbyopia, cataracts and other symptoms, so that light can not be focused on the retina, so the human to correct artificial intraocular lens(IOL) by medical research , when light enters the eye , that we can adjusted via IOL, regained focus light effect. The study is main divided into two parts, the first part is design aspheric artificial intraocular lens, that it''s can be adjusted in the state of function of use aspherical lens as the design of multifocal lens,that because aspheric have variability mirror group of more liberal in optimization process , so divided three zoom of far, middle, nearly ; the second part is design a multifocal non-adjustable type of free-form surface , mainly using a Fresnel lens (Fresnel Lens) as a crystalline lens, that without adjusting the lens to achieve a multifocal function. Due Fresnel lens is have limitations by more complicated lens group in the optimization process, so divided two zoom of far and nearly. The software is CODE V optical simulation design, that using of genetic algorithms (GA) to obtain the optimum value of the curvature, thickness, aspheric coefficients and diffraction grating, thereby to find the multifocal IOL of optimal solution, to simulate IOL corresponds far,medium, near state regulation, reducing third-order aberrations, and improve MTF. There are two different free-form surface into the pupil(5mm, 6mm), mostly in the state of analysis different pupil optimal results, when the pupil of 5mm, the simulation results in the artificial Intraocular lens all have the part of merits and inferior. In the nearly zoom of artificial Intraocular lens, GA in the Spot Diagram and MTF (spatial frequency 15cycle / mm) improvement rate averaged 10.08%, 2.86%, but in the far zoom is inferior to the CODE V respectively averaged 16.32%,10.47%; In the state of hyperopic at nearly zoom, Spot Diagram and MTF (spatial frequency 15cycle / mm) CODE V is inferior respectively average of 23.33%, 5.13%, but GA''s improvement rate is respectively average 0.1%,2.86 % in the far zoom. From the overall result seems optimize of GA and CODE V is about the same effectiveness in the pupil of 5mm SA and TAS, SAS can''t way to improve of artificial Intraocular lens in the pupil of 6mm, that the improvement rate average were inferior to CODE V optimization 0.885%, 13.59%, 4.775%, but analysts of the Spot Diagram and the MTF are have good results, that Spot Diagram can average improve of 17.27%, 11.32%. MTF (spatial frequency 15cycle / mm) can average improve of 10.78%, 10.06%. Overall optimization results which, that the aspherical of GA is to achieve improved. In the free-form surface optimization results, although optimization of the entrance pupil of 5mm as a result can''t achieve an overall improvement, but its effectiveness is with CODE V optimization similar, and in the entrance pupil of 6mm when the overall effect is have promotion, which can be learned in the overall optimization results, GA can indeed achieve the effect of improvement. Keywords：artificial Intraocular lens, Fresnel lens, aspherical lens, genetic algorithms

碩士
國立虎尾科技大學
光電與材料科技研究所
102
Vehicle lighting systems, the lens''s primary purpose is to light converge or diverge, the vast majority of lenses are spherical lenses, but for some special purpose, such as non-elliptical reflector and the design of the shading plate under the lens to be alone to create a high gradient cutoff line, a spherical lens does not apply. Therefore, we need to design a specific lens to change the direction of light, and these lenses are aspheric mirror often or free-form surfaces, previously limited computing capacity and processing technical limitations, aspheric and free form lens design and production is very difficult, however, with the computing power and by ultra-precision processing technology development, aspheric and free form lens design and manufacturing is feasible and worth developing. This research in a free surface design method of the lens surface coated free LED light source, LED light collection angle of light of each in order to achieve high utilization of the results, was found by the experimental design, the use a single twin 425lm LED light source can meet the more stringent ECE R19 F3 regulations, and allows a uniform distribution of light shape, and in no case visor shield to create a high gradient cutoff line. In this study, the derivation of free-form surfaces, and using MATLAB calculates a free form lens, optical simulation software and then to run the simulation, and implementation verification, cancellation larger reflective surface energy and shading plate coated with LED lens designed simply to light design, not only can improve the utilization of light, reducing the number of LED used to better reduce the size of the optical element, and the reflecting surface eliminating the cost of processing and manufacturing processes.

This thesis describes the tertiary structures and dynamic studies of two protein systems. The first is human γC -crystallin protein, which is present in the nucleus of the human eye lens and the other is the plant viral protein VPg (an intrinsically disordered protein) in its free as well as its protease bound forms. The structural studies described here have been carried out using high-resolution solution NMR spectroscopic methods. Project I: Determination of solution structure and dynamics of Human γC-crystallin (HGC) using NMR spectroscopy The crystallins are the most abundant proteins in the eye lens of vertebrates. These proteins are packed in short-range spatial order to provide the transparency and appropriate refractive index gradient that are required for vision. The crystallins belong to two gene families, which are categorized as the alpha and beta/gamma crystallins respectively. The classification on the basis of molecular size and structure results in the proteins being referred to as alpha, beta and gamma crystallins. Again, each of the crystallins has two or more subtypes. The stoichiometry of the subtypes of α, β and γ crystallins varies with the age of the organism, but the order of abundance remains as β > α > γ irrespective of age. The most abundant crystallins in the nucleus (central region) of eye lens are the γ -crystallins. In the human lens, only three members of the γ− crystallin family are mainly expressed i.e. γS- (HGS), γC - (HGC) and γD - (HGD). HGS is expressed postnatally and thus is present mainly in the cortical region of the lens unlike HGC and HGD crystallins, which are present in the nucleus. It is known that aging and some cataract-associated genetic mutations alter the structure of these proteins. Other point mutations result in minimum structural perturbation but with drastically lowered solubility. Mutation in the human γC -crystallin leads to congenital cataract such as Coppock-like cataract, while structural information is available for HGD & HGS but no structure is available for HGC. However, recently a model structure has been reported for HGC based on a mouse orthologous. Based on this model structure, it was argued that HGC is an insoluble protein and was explained by lower magnitude of dipole moment and fluctuation in N-terminal domain of the model structure. However it is shown that HGC is very soluble protein. Solution structure of human γC-crystallin has been determined from an analysis of multidimensional triple resonance NMR spectroscopy using distance restraints from unambiguously assigned 1H-1H NOE peaks and dihedral angle restraints from HNHA and HNHB spectra. 15N relaxation average T1 and T2 correspond to 0.729 ± 0.02 and 0.060 ± 0.04 second from 15N backbone relaxation study, which gives average rotational correlation time 10.87 ns that shows human γC-crystallin is monomer in solution of molecular weight 21 kDa (173 residues). The ensemble of 20 lowest energy structures shows a root mean square deviation of 0.60 ± 0.12 Å for the backbone atoms, and 1.03 ± 0.09 Å for all heavy atoms. The comparison between the calculated NMR structure with backbone chain atoms C`, Cα and NH, of the x-ray crystal structure of the mouse γC - crystallin shows that the structure determined here of human γC-crystallin is very similar with an RMSD of 1.3 Å, which is not surprising given the 84.5% amino acid sequence identity between the two proteins. More importantly, the NMR structure reported here shows the subtle differences in the orientation of specific residues as well as the domain interface between the human and mouse orthologs. The orientation of the calculated dipole moment for this NMR structure differs from earlier reported for model structure. However it is similar to the other known soluble proteins. The determined solution structure of human γC-crystallin also enables us to estimate the effect of cataract-associative mutations on the structure and properties of the protein. Several such mutations are already known, and the work presented here could likely shed light on the molecular basis of these cataracts. Project II: Solution structural studies of intrinsically disordered protein VPg in free and bound forms from Sesbania mosaic virus Sesbania mosaic virus (SeMV) is a plant virus, which infects the Sesbania grandiflora tree. SeMV belongs to Sobemovirus genus, which is not defined under any family. The length of this viral genome is ~4kb. This viral genome has four open-reading frames (ORF). ORF1 and ORF2 encode movement and coat proteins, respectively. ORF2 is again split into two ORFs i.e. ORF2a and ORF2b by a -1 shift in the reading frame and encode two polypeptide chains. These polypeptide chains generate several functional proteins upon polyprotein processing. Polyprotein processing is a mechanism employed by animal and plant viruses to produce several functional proteins from a single polypeptide chain. The two polyproteins expressed are catalytically cleaved by a serine protease, thus releasing the four proteins: VPg (viral protein genome linked), RdRP (RNA dependent RNA polymerase), P10, and P8. VPg (“Viral Protein genome linked”) as its name suggests, is covalently linked to the 5` end of the viral RNA. VPgs are generally known to be intrinsically disordered proteins and have many interacting partners. Intrinsically Disordered Proteins (IDPs) are not explained by the 3D structure–function dogma. However, they are important for biological functions such as molecular recognition, signal transduction and regulation. It is known that SeMV protease becomes inactive in the absence of the VPg domain at its C-terminal. VPgs of animal viruses are well studied as compared to VPgs of plant virues. The size of VPg varies across the Sobemovirus genus. It is important to know the structure of VPg since it is necessary for protease activity. The studies conducted here focus on the structural analysis of the VPg in its free and bound forms with protease (VPg complex) as well as some aspect of full-length ProVPg. For structural studies, two constructs of VPg as fusion protein with Cytb5 tag, one lacking 23 residues at its C-terminal using the pET21a(+) plasmid vector have been designed. Sub-cloning was also done to add a thrombin recognition site to remove the hexa-His tag from new constructs of full-length ProVPg and protease (PRO). These proteins were highly expressed, isotopically labeled and purified for NMR study. The sample used for structural studies of the ProVPg 23 complex was prepared using selectively protonated Ile, Leu and Val; and isotopically labeled i.e. 2H, 13C, and 15N-VPg 23 protein. VPg in its free form is an intrinsically disordered protein and this has been confirmed by its dynamic nature observed using solution NMR spectroscopy. VPg binds to its partner protease and adopts a 3D-structure, which has been shown here. The tertiary structure has been determined using distance restraints from 1HN-1HN NOEs and methyl 1HN NOEs, and dihedral angle predicted from analysis of chemical shift values. The tertiary structure of ProVPg 23 complex has one β -sheet composed of three antiparallel β-strands and an α-helix. The ensemble of 20 lowest energy structures shows a root mean square deviation of 0.42 ± 0.09 Å for the backbone atoms, and 1.09 ± 0.11 Å for all heavy atoms for residues 15 to 50 that are primarily involved in structure formation. On the other hand RMSD is 2.34 ± 0.72 Å for the backbone and 2.55 ± 0.60 Å for all heavy atoms for all residues including both termini. That the tertiary fold of VPg both in full-length ProVPg and when complexed with protease domain (PRO) are the same has been shown here. The NMR structure reported here provides a structural basis for the origin of resonances in the up-field region of one–dimensional proton spectrum of full length ProVPg. The binding surface based on the structures of ProVPg 23 complex determined here and X-ray structure of PRO; has been determined using HADDOCK. The structural model here of full length ProVPg 23 shows the presence of aromatic interaction between Trp271 of PRO and Trp46 of VPg, which is consistent with the earlier biochemical studies.