The Effect of Employing Green Chemistry Strategies on Environment

The green chemistry branch is concerned with providing the chemical compounds needed by humans in the safest way and with lowest possible energy resources consumption, to eliminate the pollution of the environment and ensure the restoration of a safe life and a clean environment. In a deep studying to the green chemistry branch and its mechanisms and principles as a science linking chemistry to the environment. The results confirmed the importance of green chemistry and the necessity to grow and develop this branch; also, the results showed the role played by the technological revolution to develop green chemistry and how it recommended with applying Green chemistry strategies in various fields, whether in industrial or even developing countries. Keywords: key words, orkforce sizing, job-shop production, holonic mode

Design and realisation of InP and InAsP QDs passively monolithic Mode-locked lasers

This thesis examines the feasibility of using Indium Phosphide and Indium Arsenide Phosphide Quantum Dots for passive mode-locking through modal gain and absorption under forward and reverse bias, a novel semi-empirical approach and experimental work on fabricated passively monolithic mode-locked lasers (MLLs). There are two device configurations used in this work. The first device is a non-lasing segmented edge-emitting laser. The device’s contact width is 50 m, and its section length is 300 m. This device is used to characterise the modal gain and modal absorption of two studied materials. The second set of devices are fabricated passively monolithic MLLs with a shallow ridge of 2 m and total cavity length of 3 mm, gain-section length of 2400 m and saturable absorber-section length of 600 m. These second set of devices are used to measure and characterise the MLLs and to evaluate the reliability of the semi-empirical approach. Both devices are broad-area lasers with cleaved facets. A novel semi-empirical approach has been established to simulate the conditions of mode-locking regimes; and accordingly, design the best-performing Indium Phosphide and Indium Arsenide Phosphide mode-locked lasers in terms of absorber-to-gain length ratio. The approach used the combination of modal gain under forward bias and modal absorption under reverse bias, with particular attention paid to absorber-to-gain length ratio. The ratios investigated are 1:4, 3:17, 1:9 and 1:19. This approach enabled the prediction that both materials with a total cavity length of 3 mm will not provide mode-locking regime or lasing when the ratio of the saturable absorber length exceeds 20%. However, InP QDs are predicted to produce ML regimes only for device designs of 1:4, 3:17 and 1:9, while InAsP QDs are predicted to produce ML for device designs of 1:4, 3:17 ,1:9 and 1:19

Children’s Social Perception of Peers’ Dento-Facial Condition: A Cross-Sectional Study

AIMS: This study aimed to compare the participant’s perceptions about their peers’ dento-facial condition with different incisal appearances (intact, discoloured, fractured, and avulsed incisors).MATERIALS AND METHODS: A cross-sectional study was conducted among schoolchildren of both primary (8-11 years) and secondary (12-14 years) levels. Each participant was asked to judge photographs with one intact and three digitally modified central incisors giving the appearance of a traumatised tooth. Data on perceptions were collected for each condition using 12 attributes (8 positive and 4 negative; scored on a 4 point Likert scale). The positive, negative and total attribute scores were analysed separately by unpaired Student’s t-test. Repeated Measures ANOVA and Bonferroni post hoc analysis was also used.RESULTS: A group of 587 children participated in the study. The perception for intact and traumatised incisors about demographic factors is well appreciated. Among the gender delineation, girls showed a significant difference in judgment between discoloured and fractured incisors. In comparison to intact incisors, positive and total attributable scores were found to be significantly higher (P < 0.001), whereas negative attribute scores were significantly lower (P < 0.001) for traumatised incisors. Pairwise comparison showed high significance (p <0.001) between the intact and traumatised incisor conditions.CONCLUSION: The results demonstrated that visible dental trauma influenced the psychosocial judgment given by children towards their peers. This judgment would, in turn, affect their level of acceptance towards such appearances. Therefore, these conditions ought to be redressed as swiftly as possible.CLINICAL SIGNIFICANCE: The primary purpose of this study was to highlight the psychosocial perceptions of children in judging their peers, regarding not only attractiveness but also intelligence, friendliness, confidence, outgoing nature, etc

Assessment of the level of awareness about paediatric cataract among the general population of Jeddah

BackgroundCataract is an extremely serious cause of visual impairment in paediatric patients worldwide, with untreated cataract being the leading cause of blindness in children.AimsThe aim of the present study was to assess the level of awareness and knowledge about paediatric cataract among the general population of Jeddah, Saudi Arabia.Methods This survey-based cross-sectional study was conducted between June and July 2018 and included a representative sample of the general population of Jeddah, Saudi Arabia. The questionnaire included a set of questions pertaining to paediatric cataract knowledge and awareness. The gathered data were analysed using Statistical Package for Social Sciences (SPSS) version 21, and the results were acquired by Pearson’s chi square tests and frequency calculations.Results In total, 678 individuals, including 51.6per cent women and 48.4per cent men, participated in the survey. Approximately 39.7per cent participants did not know whether cataract can affect the paediatric population or not. Although the majority could not recognize the risk factors and symptoms of the disease, 75.2per cent realized that it is treatable. Surgical intervention was identified as the main treatment modality by 46.9per cent participants.ConclusionOur findings suggest that the general population of Jeddah has limited knowledge about paediatric cataract. Thus, educational campaigns and programs are necessary to increase public awareness. In addition, further studies on awareness about this condition should be considered in order to prevent serious eye complications in children

Biodegradation of Some Polycyclic Aromatic Hydrocarbons by a Bacterial Consortium Isolated from the Red Sea of Jeddah

Polycyclic aromatic hydrocarbons (PAHs) are considered organic pollutants, which are stable, highly toxic, and carcinogenic. Therefore, it was necessary to find an environmentally friendly way to degrade these compounds and remove them from polluted environments. Water samples polluted with petroleum hydrocarbons were collected from the coast of Jeddah on the Red Sea - Saudi Arabia. The results of the current study showed the ability of bacterial consortium that was enriched from the coast of Jeddah, Saudi Arabia to degrade petroleum hydrocarbons wastewater, which proved its ability to degrade PAHs in saline conditions. The bacterial union degraded BENZ compound by more than 95% at the concentration of 100 and 250 mg/L, while the degradation of this compound at the concentration of 1000 mg/L was recorded about 83% while the ANT degradation rate was recorded at more than 90% at different concentrations. In addition, this study revealed the ability of bacterial consortium to treat petroleum hydrocarbons wastewater in bioreactor (CSTR) with 92.7% of COD removed under saline conditions. Hence, this study recommends the investment of bacterial consortium in the treatment of petroleum hydrocarbons wastewater in marine environments and to remove pollutants from them

InP quantum dot monolithic mode-locked lasers for ultrashort pulse generation at 735 nm

Monolithic InP/GaInP quantum dot passively mode-locked lasers are realised for the first time, emitting in the 730 nm waveband. Devices with total cavity length between 2 mm and 3.5 mm, with uncoated cleaved facets, and saturable absorber (SA) sections representing approximately 20% of the total cavity length have been found to Q-switch, mode-lock or both, depending on operating regime. The influence of bias conditions on the characteristics of lasers with a 3 mm cavity length have been explored, resulting in generation of pulses at 734.7 nm with pulse repetition rates of 12.55 GHz and pulse durations down to ≈6 ps

Association between Renal Stones Sonographic Findings and Demographic Data among Patients at Riyadh Hospitals, Saudi Arabia

Background: Ultrasound is the primary imaging modality to identify renal stones (RS) in patients with acute flank pain. This study aimed to evaluate the presence, location, and size of RS diagnosed by ultrasound in association with age, gender, and BMI among patients at Riyadh hospitals. Methods and Results: In this case-control study, a total of 250 records (130/52% for males and 120/48% for females) from 2018 to 2019 were reviewed from January to March 2020 at different hospitals in Riyadh. In this study, 150(60%) records of patients with RS and 100(40%) records of patients without RS were collected to evaluate the risk factor for RS formation in the central area of Saudi Arabia. A designed data collection sheet containing all variables (demographic and sonographic) of the study was used. Demographic data included gender, age, and body mass index (BMI). Sonographic data included RS presence (yes, no), RS location (right kidney [RK], left kidney [LK], both kidneys), and RS size (small [1cm]). The study found that RS were more common among males than females (P0.05) Conclusion: Among patients at Riyadh hospitals, females are less affected by RS than males. Gender is a significant risk factor for the development of RS. The effect of BMI is obvious on renal stone location and size

Prevalence of Comorbidities Associated With Type 2 Diabetes Mellitus In Ksa: A Cross-Sectional Study

Objective: To determine the prevalence of comorbidities associated with type 2 diabetes mellitus among the Saudi adult population. Methods: A cross-sectional study design will be employed to investigate the prevalence of comorbidities associated with Type 2 Diabetes Mellitus (T2DM) within the Kingdom of Saudi Arabia (KSA) population. This design allows for the collection of data at a single point in time, providing insights into the existing relationship between T2DM and comorbidities.Results: The study included 601 participants. The most frequent body mass index BMI value among study participants was overweight 25-29.9 kg/m2 (n= 196, 33%), followed by Normal 18.5-24.9 kg/m2 (n= 177, 29%). The frequent gender among study participants was male years (n= 356, 59%) and female (n= 245, 41%). The most frequent age among study participants was 40-50 years (n= 145, 24%), followed by 18-28 years (n= 140, 23%). The most frequent marital status among study participants was married (n= 360, 60%), followed by single (n= 160, 27%). The perceived physical activity per week among study participants, most of whom did not do any activity (n=231,38%) followed one-time activity (n=98,16%). Conclusion: The results showed that most of the study participants were overweight according to their BMI. The majority of patients had normal blood pressure. Most of the participants suffer from diabetes. In addition, most of the participants do not do any activity, and the majority of participants are non-smokers

Perceived Risk of falls among Acute Care Patients

Purpose: In an effort to lower the number of falls that occur among hospitalized patients, several facilities have begun introducing various fall prevention programs. However, the efficacy of fall prevention programs is diminished if patients do not consider themselves to be at risk for falls and do not follow recommended procedures. The goal of this study was to characterize how patients in four different acute care specialist services felt about their risk of falling while in the hospital. Methods: One hundred patients admitted to the study hospital with a Morse Fall Scale score of 45 or higher were given the Patient Perception Questionnaire, a tool designed to assess a patient's perception of their own fall risk, fear of falling, and motivation to take part in fall prevention efforts. Scores on the Morse Fall Scale were gathered through a historical assessment of medical records. Descriptive statistics, Pearson's correlation coefficients, and independent sample t tests were used to examine the data. Results: The average age was 65, and around half (52%) were men and half (48%) were women. Based on their ratings on the Morse Fall Scale, all 100 participants were classified as being at high risk for falls. However, only 55.5% of the individuals agreed with this assessment. The likelihood that a patient would seek assistance and the degree to which they feared falling both declined as their faith in their mobility improved. Patients hospitalized after a fall exhibited considerably lower confidence scores and greater fear scores than patients who had not been injured in a fall. Conclusions: Patients who have a high fall risk assessment score may not believe they are at risk for falls and may not take any steps to reduce their risk. The prevalence of falls in hospitals might be mitigated by the creation of a fall risk assessment technique that takes into account both objective and subjective factors