20 research outputs found
Grünwald Implicit Solution of One-Dimensional Time-Fractional Parabolic Equations Using HSKSOR Iteration
This paper presents the application of a half-sweep iteration concept to the Grünwald implicit difference schemes with the Kaudd Successive Over-Relaxation (KSOR) iterative method in solving one-dimensional linear time-fractional parabolic equations. The formulation and implementation of the proposed methods are discussed. In order to validate the performance of HSKSOR, comparisons are made with another two iterative methods, fullsweep KSOR (FSKSOR) and Gauss-Seidel (FSGS) iterative methods. Based on the numerical results of three tested examples, it shows that the HSKSOR is superior compared to FSKSOR and FSGS iterative methods
Efisiensi Hidrodinamis Pemecah Gelombang Tegak Komposit Balok Kotak dan Tiang Pancang dengan Pengisi Batuan
Sebagai negara kepulauan yang memiliki pantai terpanjang didunia, Indonesia membutuhkan banyak pemecahgelombang (termasuk groin dan revetment) tidak hanya untuk melindungi pantai dari penggerusan tetapi jugademi menjaga ketenangan air di kolam pelabuhan untuk manuver kapal dan operasi bongkar-muat. Akan tetapi,sampai sekarang di Indonesia, banyak konstruksi pemecah gelombang dan revetment tidak memperhatikan teknikpantai dan manajemen dengan baik. Ada banyak pemecah gelombang, groin dan revetment yang telah dibangununtuk melindungi pantai-pantai yang kritis, tetapi perencanaan dan konstruksi tidak profesional sehingga merekatidak bertahan lama. Contoh terdekat adalah Pantai Tanjung Bunga, Makassar. Beberapa groin yang dibangun diPantai Akkarena rusak hanya dalam beberapa tahun. Sebuah pemecah gelombang yang terbuat dari silindersilinderbeton, runtuh sebelum selesai. Penyebab kelangkaan pembangunan pemecah gelombang (yang baik)adalah biaya tinggi yang dibutuhkan akibat kesulitan bekerja di laut dan kebutuhan material (yang memenuhisyarat) yang sangat banyak. Studi ini mencari jalan keluar berupa pemecah gelombang (vertikal) yang terbuatdari balok-kotak, tiang-pancang dan pengisi beton. Telah diketahui bahwa pemecah gelombang gundukan batuadalah yang paling efektif meredam energi gelombang (baik transmisi maupun refleksi), dan bahkan setelahruntuh pun masih dapat berfungsi; dengan sedikit perbaikan pada kerusakan, ia akan berfungsi lagi semakin baik.Persoalan utama adalah kebutuhan material yang sangat banyak, dan sebahagian harus dalam ukuran besar.Material ini biasanya diperoleh dari peledakan gunung-gunung batu yang berkualitas baik (SG > 2.7), hal yangsekarang sulit dilakukan karena issue lingkungan. Dengan pemecah gelombang vertikal, ukuran dan jumlah batuyang dibutuhkan sangat berkurang
Establishing kidney transplantation in a low-income country: a case in Tanzania
Background
Sub-Saharan African countries, including Tanzania, have a high burden of chronic kidney diseases (CKDs) and limited capacity for the provision of services. Tanzania and other countries in the region have made signifcant improvements in the provision of services for patients with CKD, including hemodialysis. Few countries are ofering kidney transplantation services, which is the defnitive treatment for patients with CKD and kidney failure. This study was conducted to review the steps taken by Muhimbili National Hospital (MNH) to establish a kidney transplantation service in Tanzania.
Methods
This study was based on the review of the activities that were undertaken to establish kidney transplantation services at Muhimbili National Hospital in Dar es Salaam, Tanzania. It was conducted by reviewing key documents developed for kidney transplantation and interviewing key personnel who were involved in the process.
Results
Kidney transplantation services at MNH were established in November 2017; several steps were taken in the preparatory phase including training of personnel, infrastructural modifcations, and procurement of equipment and supplies. Capacity building was achieved through international collaboration with several international and local institutions, including three Hospitals in India. The transplant team, which included nephrologists, urologists, anesthesiologists, radiologists, nurses, laboratory technicians, a transplant coordinator, and a lawyer, underwent shortterm training at BLK Hospital in India. Initial transplant procedures were carried out with support from visiting personnel from BLK, Sakra, and Seifee hospitals. In total, 72 transplant surgeries were conducted, of which 39 (54.2%) were performed with visiting teams and 31 (45.8%) by the local team independently. Of the initial 39 recipients, 56.4% were males and 43.5% were aged above 46 years. About half of the donors were brothers/sisters, and 43.5% had human leukocytic antigen haplomatch. Induction immunosuppression included basiliximab in the majority (64.1%) of recipients, and all recipients received prednisolone, tacrolimus, and mycophenolate mofetil/myfortic.
Conclusions
Establishing kidney transplantation in lower-income countries, such as Tanzania, is feasible; however, it requires dedicated eforts. Collaboration with local and international institutions provided an enabling environment for the transfer of skills and access to necessary supportive services
A Class of Weighted Point Schemes for the Grünwald Implicit Finite Difference Solution of Time-Fractional Parabolic Equations Using KSOR method
Grünwald Implicit Solution for Solving One-Dimensional Time-Fractional Parabolic Equations Using SOR Iteration
Severe imported falciparum malaria among adults requiring intensive care: a retrospective study at the hospital for tropical diseases, London.
BACKGROUND: Malaria is the commonest imported infection in the UK. Malaria requiring ICU admission has a reported mortality of up to 25%. The relationship between ethnicity, immunity, and risk of malaria is complex. The Malaria Score for Adults (MSA) and Coma Acidosis Malaria (CAM) score have recently been proposed to risk stratify patients with malaria. METHODS: Retrospective study of patients with WHO severe falciparum malaria admitted to ICU at the Hospital for Tropical Diseases, London, UK. The relationship between clinical variables and risk of death or a prolonged ICU stay were examined with logistic regression. The predictive value of the MSA and CAM score were calculated. RESULTS: 124 patients were included. Cerebral malaria and acute kidney injury occurred earlier (median day 1) than acute respiratory distress syndrome (median day 3). Six patients had community acquired bacterial co-infection. Eight patients were co-infected with HIV, five of whom were newly diagnosed. The positive predictive value of a CAM score ≥2 or an MSA ≥5 for death were 12% and 22% respectively. Five patients died. No variable was significantly associated with risk of death. There were no significant differences between individuals raised in endemic countries compared to non-endemic countries. CONCLUSIONS: Mortality in patients managed in a specialist centre was low. Patients who died succumbed to complications associated with a prolonged stay on ICU rather than malaria per se. The clinical usefulness of the MSA and CAM score was limited. Co-infection with HIV was relatively common but compared to studies in children, bacteraemia was uncommon. The relationship between ethnicity and immunity to severe disease is complex