Photoelectric properties of ZnSe

Various photoelectric techniques have been exploited in an investigation of the ionization energies of donor and acceptor type defects, and the photoionization cross-sections for electrons and holes from the acceptors in single crystals of zinc selenide doped with indium, gallium or copper. Measurements of d.c. photoconductivity and infra-red quenching were made on high resistivity material, whereas low resistivity samples were fabricated into Schottky diodes for investigation using transient photocapacitance and photocurrent techniques. Interest was focussed on zinc selenide doped with indium or gallium where strong compensation effects occurred, i.e. the resistivity increased with increasing indium (gallium) content. Self-activated acceptor centres with hole ionization energies of 0.59 eV and 0.55 eV were clearly revealed by the above techniques in indium or gallium doped samples. With increasing indium concentration a new acceptor with an ionization energy of 0.41 eV appeared. This may have been responsible for the compensation effect. To ensure that the observations were not affected by the presence of unintentionally incorporated copper impurities, Schottky diodes on samples deliberately doped with copper have also been examined. The dominant copper acceptor level was clearly revealed. It lay ~ 0.67 eV above the valence band

Quantitative analysis of defects in silicon: Silicon sheet growth development for the large area silicon sheet task of the low cost solar array project

The various steps involved in the chemical polishing and etching of silicon samples are described and the data on twins, grain boundaries and dislocation pits from fifty-three (53) samples are discussed

Perception about family physicians: results of a survey of patients visiting specialist clinics for treatment

Objective: To study the perceptions about Family Medicine among patients visiting Specialist Physicians for treatment. Methods: A questionnaire based survey was conducted at the Specialist Clinic, Aga Khan University Hospital, Karachi, Pakistan, in June 2004. Trained volunteers administered the questionnaire among patients visiting Specialist Physicians for treatment. Confidentiality was ensured to all patients and written informed consent was taken as part of the ethical requirements for the conduct of the study. SPSS computer software and Microsoft Excel were used for data management. Results: A total of 100 patients visiting the Specialist Clinic were interviewed, of which fifty four (54%) were women and forty six (46%) were men. The mean age was 36.3 years. Twenty four (24%) respondents had graduate education. Being well-mannered, being familiar with a family\u27s medical history and possessing the abilities to conduct proper checkups were quoted as main characteristics of Family Physicians by thirty eight (38%), seventeen (17%) and twenty five (25%) respondents respectively. If they had a chest pain, fifty six (56%), forty three (43%) and one (1%) respondents would consult a Family Physician, Cardiologist and Chest Specialist, respectively. Conclusion: We have documented perceptions regarding family medicine among patient\u27s visiting Specialist Physicians for treatment. It is recommended that programs highlighting role and functions of family medicine should be started for the publi

Study of the superconducting properties of the Bi-Ca-Sr-Cu-O system

High Temperature Superconductivity in the Bi-Ca-Sr-Cu-O System has been observed and has attracted considerable attention in 1988. The 80 K superconductivity phase has been identified to have a composition of Bi2CaSr2Cu2Ox, while the 110 K phase as reported in the literature has a possible composition of Bi2Ca2Sr2Cu3Ox. Researchers present here a study of the electrical properties of bulk samples of the slowly cooled and rapidly quenched 2:1:2:2 system. The samples used in this study were prepared from appropriate amounts of Bi2O3, CuO, SrCO3, CaCO3

Use of folk remedies among patients in Karachi, Pakistan

BACKGROUND: The concept that food is medicine is being practiced in certain parts of the world, with positive outcomes on health of the population. We have such practice in Pakistan but it needs to be brought in line with the available scientific evidence. METHODS: The study was conducted on 270 patients, visiting the Family Practice Center, the Aga Khan University, Karachi. A questionnaire was used to collect information on the demographic profile, and the use of folk remedies for medicinal uses. RESULTS: Substantial use of folk remedies for different medical conditions has been documented. The remedies included cinnamon, ginger, cloves, cordimon, sesame oil, poppy seeds, honey, lemon, table salt, eggs and curd. The medical conditions in which folk remedies are used in respondents\u27 view, include conditions such as common cold, cough and flu to more serious conditions such as asthma, jaundice and heat stroke.CONCLUSIONS: We have found a substantial use of folk remedies for treatment of medical conditions. There is a need to organize their use on scientific lines

Distribution of lower urinary tract symptoms (LUTS) in adult women

OBJECTIVE: To determine the distribution of lower urinary tract symptoms in adult women and the frequency with which the women consulted a health care provider for their symptoms. DESIGN: Cross-sectional analytical study. PLACE AND DURATION OF STUDY: Community Health Center of Aga Khan University Hospital from November 1st to 30th, 2002. SUBJECTS AND METHODS: A trained interviewer administered a structured questionnaire to women patients or attendants aged 18 years and older coming to the center. RESULTS: Fifty-two percent of the study subjects reported having at least one or more urinary complaints in the past. Stress incontinence was the highest reported complaint (38.4%) followed by burning (34.4%), frequency (26%), painful micturition (20.4%), urge incontinence (18.8 %), incomplete emptying of bladder (14.4%), dribbling (12.4%) and poor stream (8.4%). Forty-three percent of the women with LUTS never consulted a health care provider for their problem.CONCLUSION: Although the distribution of LUTS among females was found to be high, the patients did not consider it important enough to consult a health care provider. There is a need to create awareness among females regarding LUTS and the need to consult a health care provider for their problems

The way forward to public health in Gulf Cooperation Council (GCC) countries: a need for public health systems and law

Introduction: Public health systems in the Gulf Cooperation Council (GCC) Countries are not well established. The existing systems do not match with the current health challenges and with the use of innovative technology in healthcare (diagnosis, treatment or rehabilitation). This paper is intended to give an overview of the public health situation in these countries. It discusses the need for effective and integrated system of public health laws that plays important role in addressing high priorities in public health. Conclusion: The GCC countries have the infrastructure for estab¬lishing a national public health system. However it needs an effective integrated and organized mechanism to shape this system; based on acceptable guidelines and criteria in such a way that they are institutional and capable of meeting the population needs. This system should be cost- effective and investment in health sector should be looked upon as a sustained investment in human and societal development. Despite the great efforts exerted and achievements made, there are great challenges ahead that can be overcome by exhibiting a strong political will and having a united approach of all stakeholders

Tobacco control efforts in the Gulf cooperation council countries: achievements and challenges

This paper reports a review into the current state of tobacco use, governance and national commitment for control, and current intervention frameworks in place to reduce the use of tobacco among the populations of the Gulf Cooperation Council (GCC) member states and Yemen. It further reviews structured policy-oriented interventions (in line with the MPOWER package of 6 evidence-based tobacco control measures) that represent government actions to strengthen, implement and manage tobacco control programmes and to address the growing epidemic of tobacco use. Our findings show that tobacco control in the GCC countries has witness real progress over the past decades. These are still early days but they indicate steps in the right direction. Future investment in implementation and enforcement of the Framework Convention on Tobacco Control, production of robust tobacco control legislation and the establishment of universally available tobacco cessation services are essential to sustain and strengthen tobacco control in the GCC region