Log in

Relevant bibliographies by topics / African Scientific Journal

Contents

Journal articles
Books
Book chapters
Conference papers

Academic literature on the topic 'African Scientific Journal'

Author: Grafiati

Published: 2 June 2025

Last updated: 25 July 2025

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the lists of relevant articles, books, theses, conference reports, and other scholarly sources on the topic 'African Scientific Journal.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Journal articles on the topic "African Scientific Journal"

1

RAMDI, Sofia, and ALAMI Driss EL. "Intangible Capital, a creation of value for the company but how ?" African Scientific Journal Vol 3, N°15 (2023): 694. https://doi.org/10.5281/zenodo.7564642.

Full text

Abstract:

<strong>Résumé </strong> Plusieurs auteurs et études confirment que le capital immatériel a une valeur compétitive pour l'entreprise et qu'il occupe une place probante au sein de l'organisation, et constitue de ce fait une richesse pour cette dernière. Les composantes du capital immatériel dans leur ensemble, que ce soit le capital relationnel, humain, ou environnemental, influence inéluctablement la performance d'une entreprise et contribuent positivement ou bien négativement sur les résultats financiers de

APA, Harvard, Vancouver, ISO, and other styles

2

Oumaima, Hafide, zenjali Yacoutt, Zitouni Abdelaziz, and Lafraxo Youness. "Évaluation de l'acceptabilité des TI par les professionnels : Etude empirique en utilisant la méthode Delphi Proposition d'un modèle intégré UTAUT et TTF." African Scientific Journal Vol 3, N° 16 (2023): 831. https://doi.org/10.5281/zenodo.7775132.

Full text

Abstract:

<strong>Résumé</strong> L’introduction d’une nouvelle technologie au sein des organisations constitue souvent un processus de changement et d’innovation qui peut conduire à la reconfiguration de l’organisation du travail, des rôles, voire des compétences des professionnels qui sont souvent dans l’obligation de suivre l’évolution technologique. Une technologie peut ainsi perturber et déréguler le système, obligeant l’individu soit à se repositionner dans cette nouvelle configuration, s

APA, Harvard, Vancouver, ISO, and other styles

3

le Roux, Elizabeth. "Publishing South African scholarship in the global academic community." Notes and Records: the Royal Society Journal of the History of Science 69, no. 3 (2015): 301–20. http://dx.doi.org/10.1098/rsnr.2015.0033.

Full text

Abstract:

South Africa's academic publishing history has been profoundly influenced by its colonial heritage. This is reflected in the publication of Transactions of the South African Philosophical Society (later, the Royal Society of South Africa) from 1878. Although the Society and journal sought to promote original research about South Africa, it was modelled after the Royal Society in London and formed part of an imperial scientific community. As the local higher education institutions grew more independent and research-focused, local scholarly publishing developed as well, with university presses p

APA, Harvard, Vancouver, ISO, and other styles

4

Alımoglu, Orhan, Nuray Colapkulu, and Ihsan Metin Leblebici. "The Analysis of Sub-saharan African Surgical Sublications." International Journal of Human and Health Sciences (IJHHS) 3, no. 2 (2019): 101. http://dx.doi.org/10.31344/ijhhs.v3i2.83.

Full text

Abstract:

Objectıve: Medical education and health have been accelerated in Sub-Saharan Africa (SSA) over the years, however scientific contrubition of SSA is not adequate. The aim of this study is to document the studies published by scientists from SSA.Method: This study was conducted via searching the database of PubMed by using the words “Sub-Saharan Africa AND Surgery”, between 01.01.2016 and 31.12.2016.Results and dıscussıon: A total of 582 articles were found and reviewed. Irrelevant 305 (52%) articles were excluded. There were 277 (48%) surgical articles and 82 (30%) of the studies were conducted

APA, Harvard, Vancouver, ISO, and other styles

5

S, Magwaza. "Mapping the Colorectal Cancer Screening Scientific Landscape in South Africa: A Bibliometric Analysis to Identify Inequalities." Gastroenterology Open Access Open Journal 2, no. 1 (2021): 27–34. http://dx.doi.org/10.33169/gastro.goaoj-2-107.

Full text

Abstract:

Background This paper maps scientific publications to identify areas of CRC screening that are currently receiving greatest emphasis in South African research, as means, to identify the inequality in CRC screening research. Reviewing the publications can assist to identify research funding and research capacity gaps. It can also identify potential for collaboration of authors and institutions to reduce the inequalities. Methods We used bibliometrics to identify and map the scientific publications on CRC screening related to South Africa (SA).The search utilised three databases, namely: Web of

APA, Harvard, Vancouver, ISO, and other styles

6

Papier, Joy. "Editorial." Journal of Vocational, Adult and Continuing Education and Training 6, no. 1 (2023): 5. http://dx.doi.org/10.14426/jovacet.v6i1.309.

Full text

Abstract:

It gives me great pleasure to present this brief introduction to our 2023 issue of JOVACET, now in its sixth year of publication and seeking to increase its footprint with each passing year. To illustrate these endeavours, this year saw JOVACET being accepted on two more platforms: the first is the Directory of Open Access Journals (DOAJ), and, more recently, our journal has joined the Scientific Electronic Library Online (SciELO), an open-access searchable database that is managed in South Africa by the Academy of Science of South Africa (ASSAf ), is funded by the South African Department of

APA, Harvard, Vancouver, ISO, and other styles

7

Malapela, Thembani, and Karin de Jager. "Evaluating electronic journal use and access among academic staff at the Faculty of Agriculture, University of Zimbabwe." Performance Measurement and Metrics 18, no. 2 (2017): 110–17. http://dx.doi.org/10.1108/pmm-05-2017-0020.

Full text

Abstract:

Purpose The purpose of this paper is to explore issues around access and use of subscription electronic journals by African researchers and seeks to bring to the fore the issues academics and researchers face in accessing electronic databases. Design/methodology/approach Donor-funded electronic resources have greatly improved access to essential scientific scholarly information by researchers in developing countries. Yet in Sub-Saharan Africa, researchers and libraries still complain about lack of access to scientific information, and libraries are reported to be struggling to maintain up-to-d

APA, Harvard, Vancouver, ISO, and other styles

8

Metsing, Nthabiseng. "Submitting and tracking SADJ manuscripts to be facilitated by manuscript management systems - A professional development bulletin." South African Dental Journal 75, no. 9 (2020): 475–77. http://dx.doi.org/10.17159/2519-0105/2020/v75no9a10560.

Full text

Abstract:

The South African Dental Journal (SADJ) keeps you abreast of the latest developments in dentistry, and is the only Department of Higher Education and Training accredited scientific dental journal in South Africa for publication of scientific papers, clinical articles, current dento-political information and opinion, and trade information. Members are also able to attain their CDP points by completing the online questionnaires. All SADJ online CPD Questionnaires are valid for a two-year period from the date of online publication. If you are not able to load the questionnaire to your cours

APA, Harvard, Vancouver, ISO, and other styles

9

Shai, Kgothatso B. "Interview with Prof. Kgothatso B. Shai, University of Limpopo, South Africa Afrocentric Epistemology for Social Sciences." Uchenie zapiski Instituta Afriki RAN 68, no. 3 (2024): 107–13. https://doi.org/10.31132/2412-5717-2024-68-3-107-113.

Full text

Abstract:

Kgothatso Shai is a Full Professor of Political Science and the immediate past Head of the Department of Cultural & Political Studies at the University of Limpopo in South Africa. He previously served as President of the South African Association of Political Studies (SAAPS). He is also the incumbent President of the South African Association of Public Administration and Management (SAAPAM), where he is also serving as the founding Editor in Chief of the association’s flagship Book Series. He is a National Research Foundation (NRF)-rated researcher and the author of three academic books. H

APA, Harvard, Vancouver, ISO, and other styles

10

Ansah-Mensah, Kow, Adams Osman, Clarke Ebow Yalley, and Kofi Adu-Boahen. "Global outlook of the multiplier effect of research and development on environmental sustainability." PLOS ONE 18, no. 9 (2023): e0291370. http://dx.doi.org/10.1371/journal.pone.0291370.

Full text

Abstract:

In a time of severe environmental problems and growing public and private expenditure to promote a sustainable society, studies on the impact of Research and Development (R&D) on environmental sustainability hardly ever exist. This study looked at how R&D promotes the attainment of environmentally sustainable goals, globally. Data at the country level was compiled from the United Nations-Sustainable Development Goals (UN-SDG) database and the World Bank, then processed and analysed using spatial techniques such as spatial merge, autofill, autocorrelation, and geographic weighted regres

APA, Harvard, Vancouver, ISO, and other styles

More sources

Books on the topic "African Scientific Journal"

1

Samuel, Crowther. Journal of an expedition up the Niger and Tshadda rivers undertaken by Macgregor Laird in connection with the British Government in 1854. Cambridge University Press, 2009.

Find full text

APA, Harvard, Vancouver, ISO, and other styles

2

International Journal of African Sciences (IJAS). Editions Lumumba, 2023. http://dx.doi.org/10.58610/ijas.2710.

Full text

Abstract:

Published by Editions Lumumba with the support of Afriscience, the International Journal of African Sciences (IJAS) is a bilingual interdisciplinary scientific journal (French and English) that aims to promote and disseminate African studies by providing a platform for exchange and dialogue among researchers, academics, and professionals from both Africa and around the world. The Lumumba Editions are registered with the International ISBN Agency through the Francophone Agency for International Book Numbering, under the publisher identifier: 978-2-38489. They have an international editorial com

APA, Harvard, Vancouver, ISO, and other styles

3

Nicholson, C. Brid. Documents of the Lewis and Clark Expedition. ABC-CLIO, LLC, 2018. http://dx.doi.org/10.5040/9798400641916.

Full text

Abstract:

Through its extensive use of primary source materials and invaluable contextual notes, this book offers a documented history of one of the most famous adventures in early American history: the Lewis and Clark expedition. This book is the first to situate the Lewis and Clark expedition within the political and scientific ambitions of Thomas Jefferson. It spans a forty-year period in American history, from 1783–1832, covering Jefferson's early interest in trying to organize an expedition to explore the American West through the difficult negotiations of the Louisiana Purchase, the formation of t

APA, Harvard, Vancouver, ISO, and other styles

4

Bohls, Elizabeth A., and Ian Duncan, eds. Travel Writing 1700-1830. Oxford University Press, 2008. http://dx.doi.org/10.1093/owc/9780199537525.001.0001.

Full text

Abstract:

How is the mind agitated and bewildered, at being thus, as it were, placed on the borders of a new world!' (William Bartram) 'Thus you see, dear sister, the manners of mankind do not differ so widely as our voyage writers would have us believe.' (Mary Wortley Montagu) With widely varied motives - scientific curiosity, commerce, colonization, diplomacy, exploration, and tourism - British travellers fanned out to every corner of the world in the period the Critical Review labelled the 'Age of Peregrination'. The Empire, already established in the Caribbean and North America, was expanding in Ind

APA, Harvard, Vancouver, ISO, and other styles

5

Johansen, Bruce, and Adebowale Akande, eds. Nationalism: Past as Prologue. Nova Science Publishers, Inc., 2021. http://dx.doi.org/10.52305/aief3847.

Full text

Abstract:

Nationalism: Past as Prologue began as a single volume being compiled by Ad Akande, a scholar from South Africa, who proposed it to me as co-author about two years ago. The original idea was to examine how the damaging roots of nationalism have been corroding political systems around the world, and creating dangerous obstacles for necessary international cooperation. Since I (Bruce E. Johansen) has written profusely about climate change (global warming, a.k.a. infrared forcing), I suggested a concerted effort in that direction. This is a worldwide existential threat that affects every living t

APA, Harvard, Vancouver, ISO, and other styles

Book chapters on the topic "African Scientific Journal"

1

Bulkeley, Kelly. "Benjamin Banneker." In The Scribes of Sleep. Oxford University Press, 2023. http://dx.doi.org/10.1093/oso/9780197609606.003.0006.

Full text

Abstract:

Abstract This chapter introduces the fifth dream journalist, Benjamin Banneker. Born in 1731 in a rural part of what would become the state of Maryland, Banneker was a free African American whose family worked as tobacco farmers. Banneker had a precocious intelligence and scientific curiosity, and during his life, he worked as an inventor, engineer, surveyor, and author of impressively accurate almanacs. One of the most brilliant minds of his time, Banneker recorded his dreams in a journal throughout his life, and he wrote stories involving vivid dream experiences. He was constantly under thre

APA, Harvard, Vancouver, ISO, and other styles

2

Jimenez-Castellanos Ana, Ramirez-Robles Maximo, Shousha Amany, et al. "Enhancing Research Capacity of African Institutions through Social Networking." In Studies in Health Technology and Informatics. IOS Press, 2013. https://doi.org/10.3233/978-1-61499-289-9-1099.

Full text

Abstract:

Traditionally, participation of African researchers in top Biomedical Informatics (BMI) scientific journals and conferences has been scarce. Looking beyond these numbers, an educational goal should be to improve overall research and, therefore, to increase the number of scientists/authors able to produce and publish high quality research. In such scenario, we are carrying out various efforts to expand the capacities of various institutions located at four African countries &ndash; Egypt, Ghana, Cameroon and Mali &ndash; in the framework of a European Commission-funded project, AFRICA B

APA, Harvard, Vancouver, ISO, and other styles

3

Olatokun, Wole Michael, and Ojinga Gideon Omuinu. "Predatory Open Access Journals and Attainment of Educational Sustainable Development Goals in Africa." In Advances in Library and Information Science. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-5018-2.ch004.

Full text

Abstract:

Putting into consideration the objective of the SDG 4, it would be important to note that the provision, access, and use of information resources such as open access (OA) journals is a sine qua non for quality education in Africa. Despite its importance to the education system, open access journals have been proliferated by predatory journals. Stakeholders in the OA movement and academia claim that predatory publishing is a big problem for scientific communication and could undermine development efforts. Hence, the increasing use of predatory open access journals could affect the attainment of

APA, Harvard, Vancouver, ISO, and other styles

4

Olatokun, Wole Michael, and Ojinga Gideon Omuinu. "Predatory Open Access Journals and Attainment of Educational Sustainable Development Goals in Africa." In Research Anthology on Measuring and Achieving Sustainable Development Goals. IGI Global, 2022. http://dx.doi.org/10.4018/978-1-6684-3885-5.ch026.

Full text

Abstract:

Putting into consideration the objective of the SDG 4, it would be important to note that the provision, access, and use of information resources such as open access (OA) journals is a sine qua non for quality education in Africa. Despite its importance to the education system, open access journals have been proliferated by predatory journals. Stakeholders in the OA movement and academia claim that predatory publishing is a big problem for scientific communication and could undermine development efforts. Hence, the increasing use of predatory open access journals could affect the attainment of

APA, Harvard, Vancouver, ISO, and other styles

5

Young, Chimezirim, and Ayo Oyewale. "Africa’s Journey to Industrialization." In Emerging Markets. IntechOpen, 2021. http://dx.doi.org/10.5772/intechopen.94372.

Full text

Abstract:

This chapter examines the history of other nations in achieving rapid industrialization, explains the scientific processes involved, as well as developing a model to guide Nigerians in curbing mass unemployment. This industrialized countries where selected randomly from the pool of industrialized nations, to represent the different continents. Their journey to industrialization was studied and itemized to help developing countries design a unique strategy to curb mass unemployment. The chapter adopts historical analysis to gather evidence and formulate ideas from the past and empirical analysi

APA, Harvard, Vancouver, ISO, and other styles

6

Lekan, Thomas M. "No Room for Wild Animals." In Our Gigantic Zoo. Oxford University Press, 2020. http://dx.doi.org/10.1093/oso/9780199843671.003.0003.

Full text

Abstract:

This chapter shows that Bernhard and his son Michael Grzimek’s quest to save African wildlife began on a simple collecting trip to bring a specimen of the rare Okapia from the former Belgian Congo back to the Frankfurt Zoo. The pair documented this journey in the bestselling book No Room for Wild Animals (1954), which they released as a conservationist documentary by the same name in 1956. In these works, the Grzimeks broke with colonialist images of “exotic” Africa and with Walt Disney studio’s lighthearted animal adventures popular at this time. They presented Central Africa as a region dest

APA, Harvard, Vancouver, ISO, and other styles

7

Achugbue, Edwin Iroroeavwo, and Adeyinka Tella. "Publication in High Impact Journals and Implications for University Rankings of African Universities." In Impact of Global University Ranking Systems on Developing Countries. IGI Global, 2023. http://dx.doi.org/10.4018/978-1-6684-8266-7.ch017.

Full text

Abstract:

Publication in high impact journals is part of the university norm. Currently, in most universities across the world, both government and private universities emphasise publication in high impact journals. The reason is to enable the researcher to have an impact factor that will enable him to have H-index. H-index is a single-number metric that represents the impact of an author's publications. It is a combined measure of both the researcher's publications' productivity and their visibility in terms of citation counts. The research publication is a good approach for linking the university to t

APA, Harvard, Vancouver, ISO, and other styles

8

Jackson, Helen Cassandra. "Overcoming the Myriad of Obstacles." In Critical Research on Sexism and Racism in STEM Fields. IGI Global, 2016. http://dx.doi.org/10.4018/978-1-5225-0174-9.ch004.

Full text

Abstract:

This chapter documents the experiences of the ongoing journey of an African American female physicist. They correspond to those in documented studies of other African Americans and females in both the specific field of physics as well as the broader area encompassing Science, Technology, Engineering, and Mathematics (STEM). While there are some anomalies, when scaled with the norm of these groups, there is a thread of consistencies in the obstructions and difficulties that seem to be unique to mostly African Americans and on a smaller scale to White females. The intent of this writing is to sh

APA, Harvard, Vancouver, ISO, and other styles

9

Ndelo di Phanzu, Josaphat, Lievins-Corneille Mputu Malolo, Patrick Ndelo Matondo, and Yannick Belo Nuapia. "Atmospheric Pollution and Toxicological Aspects of Helicobacter pylori Infection: Background, Pathophysiology and New Innovative Hypotheses." In Gastric Cancer - Progress and Challenges in the Era of Precision Medicine [Working Title]. IntechOpen, 2024. http://dx.doi.org/10.5772/intechopen.1005009.

Full text

Abstract:

A strange phenomenon characterized by numerous pathologies occurred in DR Congo and in some other countries of Subsaharian Africa since a few decades. While the entire population is convinced of massive poisonings provoked by a ritual poison from the eastern Africa, named Karuho, we incredibly established, since 2010, the responsibility of Helicobacter pylori in the phenomenon, thanks to cross-sectional epidemiological studies. Our findings have been published in international journals and presented in international scientific forums. The purpose of this chapter is to describe the background a

APA, Harvard, Vancouver, ISO, and other styles

10

Jackson, Helen C. "Overcoming the Layers of Obstacles." In Women's Influence on Inclusion, Equity, and Diversity in STEM Fields. IGI Global, 2019. http://dx.doi.org/10.4018/978-1-5225-8870-2.ch004.

Full text

Abstract:

This chapter documents the experiences in the journey of an African American female physicist. They correspond to those in documented studies of other African Americans and females in both the specific field of physics as well as the broader area of all STEM. When scaled with the norm of these groups, there is a thread of consistencies in the obstructions and difficulties that seem to be common to the underrepresented. This writing, which is adopted from the author's previous contribution to a similar topic, seeks to continue to reinforce the challenges women of color have experienced in pushi

APA, Harvard, Vancouver, ISO, and other styles

Conference papers on the topic "African Scientific Journal"

1

"South Africa’s Quest for Smart Cities: Privacy Concerns of Digital Natives of Cape Town, South Africa." In InSITE 2018: Informing Science + IT Education Conferences: La Verne California. Informing Science Institute, 2018. http://dx.doi.org/10.28945/4071.

Full text

Abstract:

Aim/Purpose: [This Proceedings paper was revised and published in the 2018 issue of the Interdisciplinary Journal of e-Skills and Lifelong Learning, Volume 14] The objective of this study is to investigate the impact of awareness, perceived benefits, types of data collected and perceived control on the privacy concerns of digital natives living in what is considered the smart city of Cape Town, South Africa. Background: Smart city projects have been known to bring benefits such as sustainable economic development to cities. However one may wonder what and how certain factors influence the priv

APA, Harvard, Vancouver, ISO, and other styles

2

Guedes, Pedro. "Healing Modern Architecture’s Break with the Past: Musings around Brazilian Fenestration." In The 38th Annual Conference of the Society of Architectural Historians Australia and New Zealand. SAHANZ, 2022. http://dx.doi.org/10.55939/a3990prwvx.

Full text

Abstract:

This paper focuses on the role of Brazilian architects in emancipating Modern Architecture from overly limiting orthodoxies. In particular, this study follows direct, if weak influences across the Pacific to Australia and stronger ones across the South Atlantic to Southern Africa, where Brazilian ideas found fertile ground without being filtered through Northern Hemisphere mediations. Official delegations of architects from Australia and South Africa went to Brazil seeking inspiration and transferable ideas achieved mixed success. Central to the theme of this essay is a recently discovered and

APA, Harvard, Vancouver, ISO, and other styles

3

"STRA Conference Proceedings 2023 - Volume 3." In International Conference on Science & Technology. Scientific & Technical Research Association, 2023. http://dx.doi.org/10.20319/icstr.2023.v3.

Full text

Abstract:

Scientific and Technical Research Association (STRA) is an international community of researchers, practitioners, students, and educationists for the development and spread of ideas in the field of science and technology. STRA is promoted by Eurasia Research. STRA aims to bring together worldwide researchers and professionals, encourage intellectual development, and treat opportunities for networking and collaboration. These objectives are achieved through academic networking, meetings, conferences, workshops, projects, research publications, academic awards, and scholarships. The driving forc

APA, Harvard, Vancouver, ISO, and other styles

4

Guilherme Semedo, Maria, João Rui Pita, and Ana Leonor Pereira. "Quality assessment of quinine sulfate samples in 19th and early 20th centuries in Portugal: the role of the Lusitanian Pharmaceutical Society." In 46th INTERNATIONAL CONGRESS FOR THE HISTORY OF PHARMACY. Pharmaceutical Association of Serbia, 2024. http://dx.doi.org/10.46793/ishp46.155s.

Full text

Abstract:

Cinchona bark-derived medicines such as quinine sulfate were the only effective and widely used antimalarial treatments until the mid-twentieth century. The aim of this communication is to find and discuss references to quality control of quinine sulfate samples in a Portuguese pharmaceutical journal. For this purpose, we analyzed the Jornal da Sociedade Pharmaceutica Lusitana (Journal of the Lusitanian Pharmaceutical Society). This was an important Portuguese journal, edited by the Lusitanian Pharmaceutical Society, a pharmacist’s organization (1838-1933). This journal reflects Portuguese pha

APA, Harvard, Vancouver, ISO, and other styles

5

Smit, Renee, and Leah Junck. "Coping in pandemic times: bricolage employed by first-generation engineering students." In SEFI 50th Annual conference of The European Society for Engineering Education. Universitat Politècnica de Catalunya, 2022. http://dx.doi.org/10.5821/conference-9788412322262.1433.

Full text

Abstract:

First-generation students have been a focus in higher education research over the past ten years. However, limited attention has been paid to engineering students who are the first in their generation to enter university. The paper reports on data collected as part of a longitudinal study of first-generation engineering students at a South African university during the early stages of the pandemic. First-generation students, who already face multiple difficulties in their educational journey, were confronted with a juxtaposition during the lockdown. As engineering students, they are inducted i

APA, Harvard, Vancouver, ISO, and other styles

6

Bolya, Mátyás. "A digitális gyűjtésrekonstrukció lehetőségei: az Ethiofolk projekt." In Networkshop. HUNGARNET Egyesület, 2023. http://dx.doi.org/10.31915/nws.2023.15.

Full text

Abstract:

In June, 1965, two young researchers arrived in Addis Ababa at the invitation of Emperor Haile Selassie. The purpose of György Martin (folk dance researcher) and Bálint Sárosi’s (folk music researcher) journey was to examine and explore traditional Ethiopian folklore. They were members of the Folk Music Research Group of the Hungarian Academy of Sciences, whose head was Kodály at that time. From their home institution they had received internationally renowned knowledge and expertise in folk music research, thus they wished to be among the first to explore Ethiopian folklore. Thus, one of the

APA, Harvard, Vancouver, ISO, and other styles

We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!