658 research outputs found
Workplace sleepiness: causes, consequences and countermeasures
Sleep deprivation is an epidemic problem in our society that adversely affects the quality and safety of our daily lives. At home and on the job, inadequate sleep is associated with considerable social, financial, and health-related costs, due to instability of waking functions. Research has shown that, sleep deprivation among workers, whether from sleep disorders, lifestyle or shift work, can hinder the proper performance, and in extreme cases may pose hazard to the workers themselves and their environment. Deficits in daytime performance can have profound effects in the processing industry where workers are often required to perform monotonous tasks that provide low levels of stimulation but also involve critical decision making and problem solving skills.
This study provides a comprehensive literature review of the current scientific research efforts in order to promote a better understanding of the relationship between sleep deprivation, productivity, performance, health and safety of the organizations. It highlights the consequences of insufficient sleep for workplace functioning and the ways in which workplace characteristics and lifestyle choices may affect sleep quality and quantity. Moreover, the adverse impact of poor sleep on organizations has been addressed through deficits in attention, concentration, memory, cognitive functioning and reaction time as well as increased incidence of anxiety, lower motivation and poor social relationship. Findings indicate that such destabilized behavioral outcomes can lead to increased rates of performance losses, absenteeism, physical or psychological injuries in addition to human errors and accidents.
Finally a variety of countermeasure strategies including caffeine, bright light, exercise, task design, sleep education and scheduling policies are discussed as potential measures to maintain workers\u27 alertness and performance. A preliminary survey is also presented in order to explore the performance of individuals in industrial settings and the potential impact of inadequate sleep. The results indicate the need for further research on workplace sleepiness and the potential issues to consider. It is important for managers to take such human limitations into consideration in order to decrease errors, reduce job dissatisfaction and improve organizational productivity and safety. --Abstract, page iv
The effect of silver nanoparticles on composite shear bond strength to dentin with different adhesion protocols
In Dentistry, restorative materials and oral bacteria are believed to be responsible for restoration failure. To make long-lasting restorations, antibacterial agents should be made. Inorganic nanoparticles and their nano composites are applied as good antibacterial agents. Objective The purpose of this study was to investigate the effect of silver nanoparticles on composite shear bond strength using one etch and rinse and one self-etch adhesive systems. Material and Methods Silver nanoparticles were prepared. Transmission electron microscope and X-ray diffraction were used to characterize the structure of the particles. Nanoparticles were applied on exposed dentin and then different adhesives and composites were applied. All samples were tested by universal testing machine and shear bond strength was assesed. Results Particles with average diameter of about 20 nm and spherical shape were found. Moreover, it was shown that pretreatment by silver nanoparticles enhanced shear bond strength in both etch and rinse, and in self-etch adhesive systems (pā¤0.05). Conclusions Considering the positive antibacterial effects of silver nanoparticles, using them is recommended in restorative dentistry. It seems that silver nanoparticles could have positive effects on bond strength of both etch-and-rinse and self-etch adhesive systems. The best results of silver nanoparticles have been achieved with Adper Single Bond and before acid etching
Designing an Improved Deep Learning-based Model for COVID-19 Recognition in Chest X-ray Images: A Knowledge Distillation Approach
COVID-19 has adversely affected humans and societies in different aspects.
Numerous people have perished due to inaccurate COVID-19 identification and,
consequently, a lack of appropriate medical treatment. Numerous solutions based
on manual and automatic feature extraction techniques have been investigated to
address this issue by researchers worldwide. Typically, automatic feature
extraction methods, particularly deep learning models, necessitate a powerful
hardware system to perform the necessary computations. Unfortunately, many
institutions and societies cannot benefit from these advancements due to the
prohibitively high cost of high-quality hardware equipment. As a result, this
study focused on two primary goals: first, lowering the computational costs
associated with running the proposed model on embedded devices, mobile devices,
and conventional computers; and second, improving the model's performance in
comparison to previously published methods (at least performs on par with
state-of-the-art models) in order to ensure its performance and accuracy for
the medical recognition task. This study used two neural networks to improve
feature extraction from our dataset: VGG19 and ResNet50V2. Both of these
networks are capable of providing semantic features from the nominated dataset.
To this end, An alternative network was considered, namely MobileNetV2, which
excels at extracting semantic features while requiring minimal computation on
mobile and embedded devices. Knowledge distillation (KD) was used to transfer
knowledge from the teacher network (concatenated ResNet50V2 and VGG19) to the
student network (MobileNetV2) to improve MobileNetV2 performance and to achieve
a robust and accurate model for the COVID-19 identification task from chest
X-ray images.Comment: 25 pages, 3 figures , 5 table
A Literature Survey of Neutronics and Thermal-Hydraulics Codes for Investigating Reactor Core Parameters; Artificial Neural Networks as the VVER-1000 Core Predictor
PERANCANGAN PEMBUATAN PENGAWET ALAMI TAHU PUTIH MELALUI PROSES DESTILASI DAUN NANAS MENGGUNAKAN METODE EKSPERIMEN FAKTORIAL DESAIN 23 DI DESA BELIK KAB. PEMALANG
Muzayyin Khalafi ,(2019),ā Perancangan Pembuatan Pengawet Alami Tahu Putih Melalui Proses Destilasi Daun Nanas Menggunakan Metode Eksperimen Faktorial Desain 2^3 Di Desa Belik Kab. Pemalangā, Laporan Proyek akhir Jenjang Strata Satu Teknik Industri Fakultas Teknik Universitas Pancasakti Tegal 2019.
Kemajuan teknologi menghasilkan penemuan baru di bidang pangan terutama sebagai pengganti formalin dengan penggunaan pengawet dari bahan alami. Salah satu contoh bahan pengawet alami yang memberikan efek antimikroba yang kuat dan dapat digunakan pada bahan pangan karena sifatnya yang tidak beracun dan aman bagi tubuh manusia.
Di pasaran salah satu yang di edarkan adalah tahu putih. Di suhu ruang daya penyimpanan tahu rata-rata 1-2 hari. Upaya pengawetan tahu dengan cara pengukusan dan penyimpanan dalam almari pendingin hanya mampu mengawetkan tahu selama 1 hari..
Penelitian Percobaan disusun dalam bentuk faktorial 2^3 adalah dari hasil perhitungan pembuatan pengawet alami untuk tahu putih ada 2 faktor yang memiliki pengaruh terhadap kadar protein, yaitu dari jenis bahan baku jahe, kunyit, kayu manis dan dosis ekstrak daun nanas (pengawet alami). Pada eksperimen bahwa pengawet alami untuk tahu putih mengetahui dengan jenis bahan baku dan dosis ekstrak daun nanas (pengawet alami) tertentu dapat pula memaksimalkan kadar protein dikendalikan dalam 3 level.
Hasil Uji keseragaman rata-rata jenis bahan baku dan kadar protein, tiap jenis dosis ekstrak daun nanas (pengwet alami). Plot interaksi jenis bahan baku jahe, kunyit, kayu manis dan dosis ekstrak daun nanas(pengawet alami) 100 ml, 150 ml, 200 ml. Output jenis bahan baku 50 gram dan dosis ekstrak 100 ml nilai Mean level kualitas rendah rata-rata -0,313 kadar protein terdapat penurunan sebesar -4,36 %. Output jenis bahan baku 75 gram dan dosis esktrak 200 ml Mean level kualitas sedang rata-rata 0,713 kadar protein terdapat kenaikan sebesar 9,93 %. Output jenis bahan baku 20 gram dan dosis esktrak 200 ml Mean level kualitas tinggi rata-rata 0,873 kadar protein terdapat kenaikan sebesar 12,15 %. Kesimpulanya tingkat kadar protein kualitas terbaik adalah jenis bahan baku 20 gram dan dosis ekstrak daun nanas 200 ml.
Kata Kunci : Jenis bahan baku, Dosis ekstrak Daun Nanas, Faktorial 23, Kadar Protei
Prevalence of positive findings of brain computed tomography scans in pediatric population
Objectives
Computed tomography (CT) scans are used more frequently in medical centers, increasing unnecessary requests for it as a first-line evaluation. This study aimed to investigate the rate and prevalence of abnormal findings in a brain CT scan in children at the Childrenās Hospital of Tabriz, Iran.
Materials &Methods
This study was a cross-sectional descriptive-analytical study that included all children under 15 years old undergoing a brain CT scan at the Childrenās Hospital of Tabriz, Iran. All patients who fulfilled the inclusion criteria and were referred to the Childrenās Hospital of Tabriz during the spring of 2018 entered the study. Age, gender, patient history, and clinical findings were examined. In the next step, the results of each patientās CT scan were evaluated.
Results
In this study, 108 patients were studied with a median age of 18.0 months. CT scan results were normal in seventy-four cases (68.5%), hydrocephalus was seen in 15 (13.9%), and benign infantile hydrocephalus was seen in eight (7.4%). The study revealed a statistically significant relationship between patient history and CT scan results (p=0.017). A statistically significant relationship was observed between the clinical findings and CT scan results (p=0.042).
Conclusion
Brain CT scans have more abnormal findings in patients with positive clinical findings. Although a CT scan is a highly sensitive and specifimodality in diagnosing central nervous system (CNS) abnormalities, its value depends on the underlying medical history and physical exam
Investigation of Dose Distribution in Mixed Neutron-Gamma Field of Boron Neutron Capture Therapy using N-Isopropylacrylamide Gel
AbstractGel dosimeters have unique advantages in comparison with other dosimeters. Until now, these gels have been used in different radiotherapy techniques as a reliable dosimetric tool. Because dose distribution measurement is an important factor for appropriate treatment planning in different radiotherapy techniques, in this study, we evaluated the ability of the N-isopropylacrylamide (NIPAM) polymer gel to record the dose distribution resulting from the mixed neutron-gamma field of boron neutron capture therapy (BNCT). In this regard, a head phantom containing NIPAM gel was irradiated using the Tehran Research Reactor BNCT beam line, and then by a magnetic resonance scanner. Eventually, the R2 maps were obtained in different slices of the phantom by analyzing T2-weighted images. The results show that NIPAM gel has a suitable potential for recording three-dimensional dose distribution in mixed neutron-gamma field dosimetry
Free vibration analysis of variable stiffness composite laminated thin skew plates using IGA
A NURBS-based isogeometric finite element formulation is developed and adopted to the free vibration analysis of finite square and skew laminated plates. Variable stiffness plies are assumed due to implementation of curvilinear fiberreinforcements. It is assumed due to employment of tow placement technology, in each ply of variable stiffness composite laminated plate the fiber reinforcement orientation angle is changed linearly with respect to longitudinal geometry coordinate. The classic plate theory is utilized for structural model description. The cubic NURBS basis functions are employed to approximate the geometry of the plate while simultaneously serve as the shape functions for solution field approximation in the analysis. To show the effectiveness and accuracy of the developed formulation, some representativeresults are extracted and compared to similar items available in the literature. The effects of curvilinear fiber angles, different geometries and various end constraints are evaluated on the variable stiffness composite laminated skew panel behavior
Local hyperthermia case study
Background: Prostate cancer is the second most common reason of death in men. Multidisciplinary therapy is the best treatment option, although, there is no common consent on optimal therapy for advanced prostate cancer.Case Presentation: The present study reports a case of 75 year-old man who had a huge heterogeneous soft tissue mass lesion with non-homogeneous enhancement consisted low attenuated foci occupying pelvis cavity and lower abdomen with loss of mesenteric fat and invasion to posterior bladder wall due to T4N1Mx prostate cancer. The patient was treated with adjuvant radiotherapy (RT) plus local hyperthermia (HT).Conclusion: This report shows the potential capability of HT application during RT. Radiotherapy with hyperthermia combination revealed a dramatic response in this case and after treatment it left the patient asymptomatic
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