20 research outputs found
Towards a Global Interdisciplinary Evidence-Informed Practice: Intimate Partner Violence in the Ethiopian Context
Background. Intimate partner violence is a global health issue and is associated with a range of health problems for women. Nurses, as the largest health workforce globally, are well positioned to provide care for abused women. Objectives. This nursing-led interdisciplinary project was conducted to understand the current state of knowledge about intimate partner violence in Ethiopia and make recommendations for country-specific activities to improve response to intimate partner violence through practice changes, education, and research. Methods. The project involved two phases: review of relevant literature and an interdisciplinary stakeholder forum and a meeting with nurse educators. Findings. The literature review identified the pervasiveness and complexity of intimate partner violence and its sociocultural determinants in the Ethiopian context. Two significant themes emerged from the forum and the meeting: the value of bringing multiple disciplines together to address the complex issue of intimate partner violence and the need for health care professionals to better understand their roles and responsibilities in actively addressing intimate partner violence. Conclusions. Further research on the topic is needed, including studies of prevention and resilience and “best practices” for education and intervention. Interdisciplinary and international research networks can support local efforts to address and prevent intimate partner violence
Upcycling spent brewery grains through the production of carbon adsorbents: application to the removal of carbamazepine from water
Spent brewery grains, a by-product of the brewing process, were used as precursor of biochars and activated carbons to be applied to the removal of pharmaceuticals from water. Biochars were obtained by pyrolysis of the raw materials, while activated carbons were produced by adding a previous chemical activation step. The influence of using different precursors (from distinct fermentation processes), activating agents (potassium hydroxide, sodium hydroxide, and phosphoric acid), pyrolysis temperatures, and residence times was assessed. The adsorbents were physicochemically characterized and applied to the removal of the antiepileptic carbamazepine from water. Potassium hydroxide activation produced the materials with the most promising properties and adsorptive removals, with specific surface areas up to 1120 m2 g-1 and maximum adsorption capacities up to 190 ± 27 mg g-1 in ultrapure water. The adsorption capacity suffered a reduction of < 70% in wastewater, allowing to evaluate the impact of realistic matrices on the efficiency of the materials.publishe
Electrical Reliability and Multilevel Cell Characteristics of Conductive Bridge Random Access Memory (CBRAM)
Doctor저항 스위칭 메모리(RRAM)는 기존의 메모리를 대체할 새로운 차세대 메모리인데, 특히 고밀도 메모리 응용에서 기존 메모리보다 뛰어난 성능을 발휘한다.. RRAM은 재료와 저항 스위칭 메커니즘에 따라 다른 종류들로 분류 될 수 있다. 전기 화학 금속화 셀 (electrochemical metallization cell)로도 알려진 CBRAM (Conductive Bridge Random Access Memory)은 유망되는 RRAM 중 한 종류인데, 빠른 스위칭 속도와 저전력, 높은 ON / OFF 비율, 스케일링 가능성 및 multi-level 기능을 가지고 있다. 기존의 NVM과 비교하여CBRAM은 여러 장점들과 스케일링 가능성을 가지고 있기 때문에, CBRAM 은 메모리, 논리, 신경모방, 전산 같은 다양한 응용에 가능한 비 휘발성 메모리의 유망주로서 주목 받았다.
본 논문에서는 HfO2을 고체전해질로서 이용한 Cu 계 CBRAM의 전기 신뢰성 및 다중 비트 응용에 대한 물리적 이해를 목표로 한다. CBRAM 장치의 스위칭 메커니즘은 나노 금속 필라멘트의 전기 화학적 생성과 용해 반응인데, 산화 가능한 Cu 전극과 전기 화학적으로 비활성인 PT 전극 사이에서 일어난다. 측정 조건으로부터 오는 영향과 더불어Cu / HfO2 계면에서의 얇은 Ti- diffusion barrier 층은 유지 특성, 장치의 균일성 및 multi-level 데이터 저장 능력과 같은 저항 스위칭 특성을 향상시킨다.
응용 장치 개발은 Fail 메커니즘과 최적화에 연관된 주요 매개 변수의 이해에 달려 있습니다. ON-state 저항의 데이터 보존 시간에 대한 상세 분석이 고온에서 이루어졌는데, 데이터 보유 시간의 개선은 전도성 필라멘트 (CF) 크기뿐만 아니라 전도성 필라멘트 내의 Cu 원자 농도 밀도에 의존하는 것으로 밝혀졌다. 이는 Cu +와 결합 된 구리 원자가 겹쳐졌으며, Cu 금속 필라멘트의 산화를 방지하는 Extended-state가 형성되었음을 의미한다..
재료 적층과 다른 측정 조건 이용하여 균일성을 향상시키고, 이를 통한 장치 성능 최적화가 입증되었다. 실험적 관찰은 다중 또는 수지상 결정과 같은 필라멘트의 무작위 생성이 스위칭 매개 변수의 변화에 대한 이유임을 보여준다. 우리는 1) 다른 compliance current에서의 다른 재료 적층 및 측정과 2) 낮은 compliance current에서 Ti- diffusion buffer 층을 갖는 장치가 균일성을 향상시킴을 제안한다.
또한, CBRAM에서의 multi-level 셀 거동이 제안되었다. 안정적이며 재현성 있는 양자화된 전도도(conductance) 상태는 기초 전도도의 정수 배를 가지는데, Cu / HfO2 계면에서 전압 상승 속도와 Ti 확산 장벽을 최적화하여 얻어진다. 상승 속도 최적화와Ti-diffusion에 의한 구리 이온diffusion제어를 통하여 구리이온 감소를 제어할 수 있기 때문에, 전도도 상태의 불연속적인 변화가 적어도 3 비트에서는 분명하게 관찰되었다. 다른 경우에서는, 낮은 compliance current에서 sweep 속도 제한 효과를 통한 셀 안의 multi-bits 프로세스가 연구되었다. Sweep 속도 이용한 확률적 필라멘트 형성 제어는 옴 영역에서 상이한 전도도를 만들었다. 이는 Sweep속도가 느려짐에 따라, 긴 스위칭 시간에 있는 많은 수의 원자 수가 두꺼운 필라멘트가 만들기 때문이다.
전도성 필라멘트의 미세 구조 변경을 통한 multi-level 데이터 저장의 물리적 이해를 명확히 하기 위해 물리 기반 모델링이 수행었다. 한정된 필라멘트의 영역에서 양자점 접촉을 계산함으로써, 원자 재배열에 의한 필라멘트의 수축 크기의 변경은 불연속적인 전도도 변화를 만듦을 알아냈다. Potential barrier는 주입 된 원자 수와 관련되어 있는데, 수축 크기는 potential barrier를 조절함으로써 변화된다. 이 접근법은 mutil-level 응용을 위한 탁월한 양자화 전도도를 가진 미래 CBRAM 장치의 실현 가능성을 확인하였다.Resistive switching memory is the new class of memories for future memory replacement, in particular for high density memory application. RRAM technology could be categorized to different groups regarding to material and mechanism for resistance switching. Conductive bridge random access memory (CBRAM) which also known as electrochemical metallization cell is one sub-class of emerging RRAM which involve fast switching speed, low power, high ON/OFF ratio, scaling potential and multi-level capability. From the point view of its advantage and scaling potential with respect of the conventional NVM, CBRAM concept has drawn attention for a potential candidate for non-volatile memory carrying different application like, memory, logic concepts, neuromorphic and computing application.
In this thesis, we attempt to develop physical understanding for electrical reliability and multi-bits application with Cu-based CBRAM using HfO2 as solid electrolyte. The switching mechanism of CBRAM device is an electrochemical formation and dissolution of nanometallic filament between an oxidizable Cu electrode and an electrochemically inert electrode (Pt). Thin Ti-diffusion barrier layer at interface of Cu/HfO2 with combined effect of measuring condition was improve the resistive switching characteristics, such as retention properties, uniformity of the device and multilevel data storage application.
The development of the device for application depends on the understanding of the failure mechanism and the key parameters for device optimization. The detail analysis of data retention time of ON-state resistance investigated at high temperature. It is found that the improvement of data retention time depends not only on the conductive filament (CF) size but also on Cu atoms concentration density in the conductive filament. That means, the copper atoms associated with Cu+ overlap and an extended state formed which is prevent the easily oxidation Cu metal filament.
The optimization of device performance through the improvement of the uniformity based on the material stack and different measuring condition are demonstrate. The experimental observation shows the random generation of filament like multiple or dendrite kinds are the reason for variation of switching parameters. We propose different material stack and measurements at different compliance current and the device with Ti-diffusion buffer layer at low compliance current show the improvement of uniformity.
Furthermore, multilevel cell behavior in conductive bridge random access memory was proposed. Stable and reproducible quantized conductance states with integer multiples of fundamental conductance obtained by optimizing the voltage ramping rate and the Ti-diffusion barrier at the Cu/HfO2 interface. Owing to controlled Cu ions diffusion by the Ti-diffusion and the optimize ramping rate, through which it was possible to control the time delay of Cu ion reduction, a discrete change of conductance states was clearly observed at least for three bits. In other case, through sweep rate limiting effect at low compliance current, multi-bits process studied in the cell. Controlling the stochastic filament formation through sweep rate gives different conductance level at the ohmic region. This is due to more number of atoms make thicker and thicker filament in the long time of switch as sweep rate become lower and lower.
Physics based compact modeling was performed to clarify the physics of multilevel data storage through the microstructure modification of conductive filament. By accounting quantum point contact at the confined region of the filament, the modification of constriction size of the filament through atomic rearrangement makes the discrete change of conductance. The constriction size modulate through the control of the potential barrier in the constriction which is related to the number of atoms injected in the constriction. The approach confirmed the feasibility of future CBRAM device with excellent quantized conductance for multi-level application
Hypertension self-care practice and associated factors among patients in public health facilities of Dessie town, Ethiopia
Abstract Background Hypertension self-care practice is essential for blood pressure control and reduction of hypertension complications. Nevertheless, we know little concerning hypertension self-care practice in Ethiopia. The purpose of this study was to assess hypertension self-care practice and associated factors among patients in public health facilities in Dessie town, Ethiopia. Methods In this cross-sectional study, 309 hypertensive patients (mean age 58.8 years, 53.4% women) completed the interviewer-administered questionnaire in Amharic language. Descriptive and logistic regression analyses were conducted using SPSS version 22. Result The mean score for hypertension self-care was 37.7 ± 8.2 and 51% scored below the mean. Divorced participants (AOR = 0.115, 95% CI = 0.026, 0.508, p-value < 0.01) and those who lack source of information (AOR = 0.084, 95% CI = 0.022, 0.322, p-value < 0.01) were less likely to have good self-care practice. But, participants who had convenient place for exercise (AOR = 2.968, 95% CI = 1.826, 4.825, p-value < 0.01), who had good social support (AOR = 2.204, 95% CI = 1.272, 3.821, p-value < 0.01), who had traditional clergy-based teaching (AOR = 2.209, 95% CI = 1.064, 4.584, p-value < 0.05), and who had good self-care agency (AOR = 1.222, 2.956, p-value < 0.05) were more likely to have good self-care practice. Conclusion Most of the study participants reported poor self-care practices. Factors associated with hypertension self-care practice are marital status, education, source of self-care information, place for exercise, social support, and self-care agency. Targeted interventions are needed to improve hypertension self-care practice
Knowledge and self-reported practice of insulin injection device disposal and associated factors among diabetes patients in Addis Ababa, Ethiopia: A cross-sectional study
Background: Diabetes mellitus is a serious long-term condition with a major impact on the lives and well-being, of societies worldwide. Poor disposal practices of devices potentially result in personal injury and injuries to people in the household and the general community. This study aimed to assess the knowledge and self-reported practice of insulin injection device disposal and associated factors among diabetes patients in TASH, Addis Ababa, Ethiopia. Method: A cross-sectional study was conducted among 182 adults with diabetes. The study participants were selected through systematic random sampling. Data were collected from March/17/2020 - May/18/2020. Patients were interviewed using a structured questionnaire. Data were entered into Epi-data version 4. 6 and exported to SPSS version 25.0 for analysis. Bivariable and multivariable logistic regression with crude and adjusted odds ratios along with the 95% confidence interval was computed and interpreted accordingly. Good practice and adequate knowledge were defined based on median calculation; a result above the median value of good practice and adequate knowledge with a p - value < 0.05 was considered to declare a result as statistically significant.Results: About 54% of the participants had inadequate knowledge about safe insulin injection waste disposal. More than two-thirds (73%) of respondents had poor practice and 92.3% of respondents did not know how to dispose of lancets after use.Conclusion: This study revealed that the knowledge and practice of diabetic patients were inadequate and poor towards safe insulin injection waste disposal in the study area. Educating patients and awareness creation training on proper insulin injection device disposal should be considerable. 
Factors associated with self-care practice among adult diabetes patients in West Shoa Zone, Oromia Regional State, Ethiopia
Abstract Background Diabetes, a rising global health problem, requires continuous self-care practice to prevent acute and chronic complications. However, studies show that few diabetes patients practice the recommended self-care in Ethiopia. The aim of this study was to assess factors associated with self-care practice among adult diabetes patients in public hospitals of West Shoa Zone, Oromia Regional State, Ethiopia. Methods In this cross-sectional study, 257 diabetes patients (mean age 42.9 ± 14.6 years, 54.1% male) completed the survey in Afan Oromo and Amharic languages. A questionnaire consisting standardized tools was used to collect the data. Descriptive and logistic regression analyses were conducted using SPSS version 21. Results The mean score for diabetes self-care was 39.8 ± 9.5 and 45.5% of the participants scored below the mean. Multiple logistic regression analysis revealed that having higher diabetes knowledge (AOR = 2.42, 95% CI = 1.22, 4.80), self-efficacy (AOR = 3.30, 95% CI = 1.64, 6.62), social support (AOR = 2.86, 95% CI = 1.37, 5.96), secondary school education (AOR = 6.0, 95% CI = 1.90, 18.85), and longer duration of diabetes (AOR = 5.55, 95% CI = 2.29, 13.44) were important predictors of good diabetes self-care practice. Conclusion The diabetes education programs should use strategies that enhance patients’ diabetes knowledge, self-efficacy, and social support. Patients with recent diabetes diagnosis need special attention as they may relatively lack knowledge and skills in self-care. Further studies are needed to elucidate pathways through which diabetes knowledge, self-efficacy, social support, and health literacy affect diabetes self-care
Theoretical Performance Analysis of Inverted P3HT: PCBM Based Bulk Hetero-Junction Organic Solar Cells through Simulation
In this study, the role of active layer thickness, hole transport layer thickness, and electron mobility on the performance of P3HT: PCBM-based inverted organic solar cells has been investigated. The simulation has been done for device structure ITO/ZnO/P3HT: PCBM/MoO3/Ag using the general-purpose photovoltaic device model (GPVDM) program tool. The short circuit current density (Jsc), open circuit voltage (Voc), fill factor (FF), and power conversion efficiency (PCE) of the cell were determined by varying the thickness of the active layer from 140 nm to 260 nm, the hole transparent layer from 10 nm to 40 nm, and electron mobility from 0.5 × 10−3 cm2V−1s−1 to 6.5 × 10−3 cm2V−1s−1. The PCE improvement was observed at 220 nm and 20 nm active layer and hole transporting layer thickness, respectively, for 4.5 × 10−3 cm2V−1s−1 electron mobility. The results confirmed that the thickness of the active layer, hole transport layer, and charge carrier mobility plays an important role in the performance improvement of organic solar cells
Controllable quantized conductance for multilevel data storage applications using conductive bridge random access memory
In this paper, we investigate the quantized conduction behavior of conductive bridge random access memory (CBRAM) with varied materials and ramping rates. We report stable and reproducible quantized conductance states with integer multiples of fundamental conductance obtained by optimizing the voltage ramping rate and the Ti-diffusion barrier (DB) at the Cu/HfO2 interface. Owing to controlled diffusion of Cu ions by the Ti-DB and the optimized ramping rate, through which it was possible to control the time delay of Cu ion reduction, more than seven levels of discrete conductance states were clearly observed. Analytical modeling was performed to determine the rate-limiting step in filament growth based on an electrochemical redox reaction. Our understanding of the fundamental mechanisms of quantized conductance behaviors provide a promising future for the multi-bit CBRAM device.112Nsciescopu
Knowledge of stroke risk factors and warning symptoms among adults with type 2 diabetes in Addis Ababa, Ethiopia, 2021: an institution-Based cross-sectional study
Abstract Background Stroke is a global public health concern with type 2 diabetes being one of the common risk factors. Knowledge of stroke risk factors and warning symptoms among type 2 diabetes patients is largely unknown in developing countries like Ethiopia. The inability to recognize stroke warning symptoms accurately is an important cause of delay in seeking medical attention. We investigated knowledge of stroke risk factors and warning symptoms among adults with type 2 diabetes and the factors associated with these variables. Methods This was an institution-based cross-sectional study. We enrolled 470 adult type 2 diabetes patients using a systematic random sampling method from four government-managed hospitals in Addis Ababa from 1 to 30 February 2021. The Stroke Recognition Questionnaire was adapted to measure the knowledge of stroke risk factors and warning symptoms. Sociodemographic characteristics, source of information, and reaction to stroke were also measured. Data were analyzed using SPSS version 25 and linear regression analysis was used to determine factors independently associated with knowledge of stroke risk factors and warning symptoms. Result The mean age of the participants was 50.6 ± 12.9 years. The mean score of knowledge of stroke risk factors and warning symptoms was 67.2% and 63.9%, respectively. Higher educational level (B = 2.007, 95% CI = 1.101, 2.914, P < 0.001), knowing someone diagnosed with stroke (B = 3.328, 95% CI = 2.734, 3.922, P < 0.001), and living with others (B = 2.28, 95% CI = 1.606, 2.954, P < 0.001) were independently associated with knowledge of stroke risk factors. Younger age (B = − 0.021, 95% CI= -0.038, 0.005, P = 0.01), higher educational level (B = 1.873, 95% CI = 1.017, 2.730, P < 0.001), and knowing someone diagnosed with stroke (B = 3.64, 95% CI = 3.079, 4.200, P < 0.001) were independently associated with knowledge of warning symptoms of stroke. Conclusion The mean score of knowledge of stroke risk factors and warning symptoms was 67.2% and 63.9%, respectively. Younger age, higher educational level, and living with other people are predictors of better knowledge of stroke risk factors and warning symptoms in this study. Future educational interventions should target type 2 diabetes adults with advancing age and the involvement of their family members