Soil Organic Matter Dynamics Upon Secondary Succession in Imperata Grassland, East Kalimantan, Indonesia

Soil organic matter (SOM) dynamics upon secondary succession in Imperata grassland was studied by stable carbon isotope analysis. The data of litter and soil samples of twenty plots in four different stages of succession were compared. These different stages were represented by plots that were; (1) last burned 3 years before sampling (Imperata grassland), (2) last burned 9 years before, (3) a secondary forest (≥15 years) and (4) a primary forest. Result showed that isotopic signatures of all soil horizons of the regeneration stages were statistically different from those of the primary forest. The A-horizon under the 3-years Imperata plot still contained 23% forest (C3) carbon, and this fraction increased to 51% in the-B-horizon. In the 9-years plot and in the secondary forest, the C3 carbon on the A-horizon increased to 51% and 96%, respectively. In the topsoil, the loss of C4-C between the 3-years and the 9-years plot was significant, while it appeared negligible in the AB-horizon. The strong decay in the topsoil under Imperata grassland may be due to the rather high carbohydrate content of the SOM, which is considered easily decomposable. Further research is needed especially to explore the relation between carbon stocks and chemical of SOM composition. Such insight may help to better understand and predict soil carbon changes in relation to climate and vegetation change

A hydrodynamic model for biomass gasification in a circulating fluidized bed riser

This study presents a three-dimensional Computational Fluid Dynamic (CFD) model and experimental measurements of the hydrodynamics in the riser section of a Circulating Fluidized Bed (CFB) biomass gasifier consisting of a binary mixture of polydisperse particles. The model is based on multi-fluid (Eulerian-Eulerian) approach with constitutive equations adopted from the Kinetic Theory of Granular Flow (KTGF). The study first presents an assessment of the various options of the constitutive and closure equations for a binary mixture followed by sensitivity analysis of the model to the solution time step, cell size, turbulence and the alternative formulations of the granular energy equation. Accordingly, a robust and reliable hydrodynamic model is recommended and validated using conventional pressure measurements and Positron Emission Particle Tracking (PEPT) technique. Furthermore, the model predictions and experiments revealed evidence of the particle re-circulation within the lower part of the riser, which is an important feature contributing to rapid mass and heat transfer in a CFB gasifier. The present hydrodynamic model can be further developed; by incorporating appropriate reactions and heat transfer equations, in order to fully predict the performance and products of a CFB biomass gasifier

Design of a Patient Wrist Rehabilitation Device with Servo Motor Drive

Stroke represents a condition that occurs when the blood supply to the brain is interrupted or reduced due to a blockage (ischemic stroke) or rupture of a blood vessel (hemorrhagic stroke). A person who suffers a stroke will have a brain disorder that causes him/her unable to carry out activities like other healthy people. In general, stroke sufferers have paralysis in several parts of the body, like the hands, feet, and even the face. With technological developments in this era, stroke can be healed in various ways that have been developed by health experts. Healing can be referred to the treatment result for blocked or damaged blood vessels. However, the sufferer’s paralysis cannot return to the normal condition immediately, so it requires therapy or exercises to stimulate the muscles in the hands, feet, or face. This study focuses on developing a therapeutic device on the wrist that has a swivel joint. To design the wrist rehabilitation device with servo motor drive, some researches about existing products need to be reviewed. From that, a list of requirements is compiled, which is used for designing the concept of a wrist rehabilitation device. It is expected that an automatic wrist rehabilitation device can help post-stroke patients undergo the rehabilitation process

Kebijakan Penilaian Keberhasilan Reklamasi Lahan Pasca-tambang Batubara di Indonesia

Indonesian government has enacted regulations requiring reclamation and rehabilitation activities on post coal mining areas. However, the evaluation related to the ecological restoration concepts is yet unavailable. This study aims to evaluate the regulations on rehabilitation and reclamation of post coal mining areas in Indonesia conforming on ecological restoration concepts. Employing desk study and content anaysis, this research focussed on three technical regulations concerning reclamation guidance and post-mining evaluation guidance, namely ESDM Decree No 7 Year 2014, MoF Decree No P.60/Menhut-II/2009, and MoF Decree No P.4/Menhut-II/2011. Each regulation was comprehensively evaluated whether the regulation already regulates matters relating to ecological restoration criterias, such as biodiversity recovery, soil remediation, planting of local plants, bans on invasive plant species and monitoring and evaluation. The result showed that there was no regulation complying with all ecological restoration criterias. Meanwhile, all the regulations have mandated monitoring and evaluation after rehabilitation and reclamation activities. However, there was no regulation mandating prohibition on planting invasive plant species. In conclusion, regulations related to post coal mining rehabilitation and reclamation have not fully complied with the ecological restoration concepts, therefore improvement to that regulations are necessary. Pemerintah Indonesia telah menetapkan berbagai peraturan yang mewajibkan kegiatan reklamasi dan rehabilitasi pasca-tambang, namun, belum banyak dilakukan evaluasi terhadap peraturan tersebut dalam kaitannya dengan konsep ekologi restorasi. Penelitian ini bertujuan untuk mengetahui sejauh mana peraturan-peraturan tersebut memenuhi konsep restorasi ekologi. Metode penelitian ini adalah desk study dengan bahan utama regulasi yang berkaitan dengan kegiatan reklamasi dan rehabilitasi lahan pasca-tambang batubara. Analisis data dilakukan dengan metode analisis isi. Kajian difokuskan pada tiga aturan teknis yang mengatur pedoman reklamasi maupun pedoman penilaian keberhasilan reklamasi pasca-tambang yaitu Peraturan Menteri ESDM Nomor 7 tahun 2014, Permenhut Nomor P.60/Menhut-II/2009, dan Permenhut Nomor P.4/Menhut-II/2011. Setiap peraturan Perundangan dikaji secara komprehensif apakah peraturan tersebut sudah memuat dan mengatur hal-hal yang berkaitan dengan beberapa kriteria restorasi ekologi. Hasil penelitian menunjukkan bahwa tidak ada peraturan yang memenuhi semua kriteria restorasi ekologi. Semua regulasi telah memuat kewajiban rehabilitasi atau reklamasi serta evaluasi tetapi tidak ada satupun regulasi yang memuat pelarangan penggunaan tanaman invasif. Kesimpulan penelitian ini adalah regulasi tentang rehabilitasi dan reklamasi pasca-tambang batubara di Indonesia belum sepenuhnya sejalan dengan konsep ekologi restorasi karena hanya memuat sebagian dari kriteria dan indikator restorasi ekologi sehingga masih diperlukan penyempurnaan agar perbaikan dan pemulihan lahan pasca-tambang dapat memenuhi konsep restorasi ekolog

Perancangan Alat Rehabilitasi Pergelangan Tangan Pasien Pasca Stroke yang Digerakkan Motor Servo

Stroke merupakan kondisi yang terjadi ketika pasokan darah ke otak terganggu atau berkurang akibat penyumbatan (stroke iskemik) atau pecahnya pembuluh darah (stroke hemoragik). Seseorang yang mengidap penyakit stroke akan mengalami gangguan pada otak yang menyebabkan tidak bisa menjalani aktifitas seperti manusia normal. Pada umumnya, pasien stroke mengalami kelumpuhan pada beberapa bagian tubuh, seperti tangan, kaki, bahkan wajah. Dengan berkembangnya teknologi pada era ini, penyakit stroke bisa disembuhkan dengan berbagai metode dari para ahli kesehatan. Sembuh yang dimaksudkan adalah hasil dari penanganan untuk pembuluh darah yang tersumbat atau pecah. Namun, kelumpuhan yang dialami penderita tidak bisa langsung kembali seperti semula, membutuhkan beberapa terapi atau latihan untuk menstimulus otot pada tangan, kaki, ataupun wajah. Pada penelitian ini, difokuskan untuk terapi pada pergelangan tangan yang mempunyai sendi putar. Untuk pembuatan konsep alat rehabilitasi pergelangan tangan yang digerakkan motor servo ini diperlukan beberapa kajian pada produk-produk yang sudah ada. Dari pengkajian produk eksisting, akan disusun daftar kebutuhan atau List of Requirements yang berguna untuk membuat konsep desain alat rehabilitasi ini. Diharapkan pada penelitian ini, diperoleh alat rehabilitasi pergelangan tangan otomatis yang bisa membantu pasien pasca stroke dalam menjalani proses rehabilitasi

Improved control of grid-connected DFIG-based wind turbine using proportional-resonant regulators during unbalanced grid

The quality of power and current control are the greatest challenges of grid-connected wind farms during abnormal conditions. The negative- and positive-sequence components of the grid currents may be injected into a wind generation system during grid faults, which can affect the power stability and damage the wind system. The proposed work assures a low-voltage ride through capability of doubly-fed induction generator- based wind turbines under the grid voltage sag. A new technique to protect the wind system and to recompense the reactive power during failures of the utility grid according to the Spanish grid code is proposed. The control design is implemented to the power converters, and the grid current regulation is developed by using proportional-resonant regulators in a stationary two-phase (alpha beta) reference frame. The control performance is significantly validated by applying the real-time simulation for the rotor-side converter and the hardware in the loop simulation technique for the experiment of the generator's grid-side converter control.This work was supported by: the project "Nuevas topologias para convertidores en MT para grandes Instalaciones Fotovoltaicas" from the Spanish Government (Ref. TEC2016-80136-P) (from A.B.R.); the European Community's Horizon 2020 Program (H2020/2014-2020) in project "ERIGrid" (grant ggreement No. 654113) under the Trans-national Access (TA) User Project (Ref. 04.003-2018); and the Erasmus + KA107 mobility program 2018/2019 between Europe and Morocco, Universidad Politecnica de Cartagena (UPCT) & Sidi Mohamen Ben Abdellah University (USMBA)-Fez (from Y.E.K.)

Diagnostic challenge for ovarian malignant melanoma in premenopausal women: Primary or metastatic?

<p>Abstract</p> <p>Background</p> <p>In the ovary, metastatic malignant melanoma may be confused with primary malignant melanoma and presents a diagnosis challenge. Most cases are associated with disseminated diseases and poor prognosis. We present this case report of a metastatic ovarian malignant melanoma simulating primary ovarian cancer.</p> <p>Case report</p> <p>A 45-year-old premenopausal woman was incidentally found to have an abdominal mass, 3 years after removal of a cutaneous melanoma lesion. Ultrasound and CT scan revealed left two solid masses, which were found to be an ovarian tumor at laparotomy. Left oophorectomy was performed. Histopathology and immunohistochemistry showed melanoma metastasis to the ovary. Nine months later, the patient developed epilepsy and confusion. Magnetic Resonance Imaging showed unique Wright frontal lobe lesion. She underwent stereotactic radio surgery and dacarbazine monotherapy. For months later, the patient is died from disseminate disease progression.</p> <p>Conclusion</p> <p>Ovarian metastasis is an unusual presentation of cutaneous melanoma and the prognosis was dismal. As illustrated by this case report, a differential diagnosis of a metastatic malignant melanoma must be considered.</p

The Etiology of Kidney Failure in Indonesia: A Multicenter Study in Tertiary-Care Centers in Jakarta

Background: Despite a large number of patients requiring dialysis, the etiology of kidney failure is poorly documented in Indonesia. With the aim to reduce the disease burden, it is essential to obtain more insight in the etiology of chronic kidney disease (CKD). Objective(s): In the present study, we attempted to investigate the primary renal disease of kidney failure patients from five tertiary-care centers in Jakarta. Methods: This is a multicenter, cross-sectional study of kidney failure patients receiving kidney replacement therapy (KRT), from December 2021 to July 2022. We recruited patients aged ≥18 years, had been receiving dialysis for at least three months or a kidney transplantation. Findings: This study included 1,152 patients treated with hemodialysis (68.1%), peritoneal dialysis (7.5%), and kidney transplantation (24.4%). At the start of KRT, the median (interquartile-range [IQR]) age was 48 [37–58] years with low eGFR (median [IQR]: 5.9 [4.0–8.34] ml/minute/1.73 m2). Hypertension was the main comorbidity (74.2%), followed by diabetes mellitus (30.1%). The major primary kidney disease was diabetic kidney disease (27.2%), followed by glomerulonephritis (13.0%), hypertension (11.5%), and urolithiasis (10.3%). Lupus nephritis was the common underlying etiology of secondary glomerulonephritis (91%). A high rate of unknown cause (31.1%) was also observed. Conclusions: Our results suggest that diabetic kidney disease is the leading cause of kidney failure in Jakarta, followed by glomerulonephritis. This study highlights the need for a better approach on primary prevention of diabetes mellitus as well as to better recognize glomerulonephritis at earlier stage might have a significant impact on reduction of the rate of kidney failure in Indonesia

Phylogeography and Population Structure of Glossina fuscipes fuscipes in Uganda: Implications for Control of Tsetse

Glossina fuscipes fuscipes is the most common species of tsetse in Uganda, where it transmits human sleeping sickness and nagana, a related disease of cattle. A consortium of African countries dedicated to controlling these diseases is poised to begin area wide control of tsetse, but a critical question remains: What is the most appropriate geographical scale for these activities? To address this question, we used population genetics to determine the extent of linkage between populations of tsetse confined to discrete patches of riverine habitat. Our results suggest that Uganda was colonized by two distinct lineages of G. f. fuscipes, which now co-occur only in a narrow band across central Uganda. Evidence for interbreeding at the zone of contact and movement of genes from the south to the north suggest that this historical genetic structure may dissolve in the future. At smaller scales, we have demonstrated that exchange of genes among neighboring populations via dispersal is at equilibrium with the differentiating force of genetic drift. Our results highlight the need for investment in vector control programs that account for the linkage observed among tsetse populations. Given its genetic isolation and its location at the far edge of G. fuscipes' range, the Lake Victoria region appears to be an appropriate target for area wide control