Heat transfer research on enhanced heating surfaces in pool boiling

The paper focuses on the analysis of the enhanced surfaces in such applications as boiling heat transfer. The testing measurement module with enhanced heating surfaces was used for pool boiling research. Pool boiling experiments were conducted with distilled water at atmospheric pressure in the vessel using an enhanced sample as the bottom heating surface. The samples are soldered to a copper heating block of the round cross-section .They were placed: in the fluid (saturation temperature measurement), under the sample for temperature determination. A vessel made of four flat glass panes was used for visualization. The heated surfaces in contact with the fluid differed in roughness were smooth or enhanced. This paper analyzes the effects of the microstructured heated surface on the heat transfer coefficient. The results are presented as relationships between the heat transfer coefficient and the heat flux and as boiling curves. The experimental data obtained for the two types of enhanced heated surfaces was compared with the results recorded for the smooth heated surface. The highest local values of the heat transfer coefficient were reported for the enhanced surfaces

PEMBUATAN ALAT PENYARINGAN AIR SEDERHANA

Tewai Baru adalah salah satu desa di wilayah Kecamatan Sepang, Kabupaten Gunung Mas, Provinsi Kalimantan Tengah, Indonesia. Desa Tewai Baru dibentuk pada tahun 1930-1950. Desa Tewai Baru berbatasan dengan Desa Tanjung Karitak di bagian utara, Kabupaten Kapuas di bagian timur, Kelurahan Sepang Simin dan Desa Sepang Kota di bagian selatan dan Kecamatan Rungan dan Kelurahan Sepang Simin di bagian barat. Jarak Desa Tewai Baru dari pusat pemerintahan kecamatan (Kecamatan Sepang) sejauh 6,9 Km, jarak Desa Tewai Baru dari ibukota kabupaten (Kuala Kurun) sejauh 59 Km dan jarak Desa Tewai Baru dari ibukota provinsi (Palangka Raya) sejauh 102 Km. Luas wilayah Desa Tewai Baru sebesar 5.300 Ha. Jumlah penduduk berdasarkan hasil sensus pada tahun 2022 adalah sebanyak 1.182 jiwa dengan penduduk laki-laki sebanyak 606 jiwa dan penduduk perempuan sebanyak 576 jiwa. Kondisi ekonomi warga di Desa Tewai Baru memiliki pendapatan yang berbeda-beda. Hal ini dikarenakan oleh profesi warga yang berbeda, dimana mayoritas berprofesi sebagai petani dan peternak, selain itu warga berprofesi sebagai pedagang. Kondisi sosial budaya yang ada di Desa Tewai Baru, masyarakat yang tinggal di desa masih melestarikan adat istiadat seperti mengadakan ritual Pakan Sahur Lewu yang dilakukan satu tahun sekali dan tradisi gotong royong mengangkat rumah atau memindahkan rumah ke tanah yang lain. Desa Tewai Baru belum memiliki ketersediaan air bersih yang cukup, karena pasokan air bersih hanya berasal dari satu PDAM yang ada di desa. Keterbatasan air bersih dari PDAM mengakibatkan warga menggunakan pompa air untuk membuat sumur bor hingga kedalaman sekitar 20 meter dengan kualitas air berminyak dan berkarat, jika didiamkan selama satu malam maka karat di dalam air tersebut akan mengendap sehingga membuat air menjadi keru

Safety and immunogenicity of the two-dose heterologous Ad26.ZEBOV and MVA-BN-Filo Ebola vaccine regimen in children in Sierra Leone: a randomised, double-blind, controlled trial

Background—Children account for a substantial proportion of cases and deaths from Ebola virus disease. We aimed to assess the safety and immunogenicity of a two-dose heterologous vaccine regimen, comprising the adenovirus type 26 vector-based vaccine encoding the Ebola virus glycoprotein (Ad26.ZEBOV) and the modified vaccinia Ankara vectorbased vaccine, encoding glycoproteins from the Ebola virus, Sudan virus, and Marburg virus, and the nucleoprotein from the Tai Forest virus (MVA-BN-Filo), in a paediatric population in Sierra Leone. Methods—This randomised, double-blind, controlled trial was done at three clinics in Kambia district, Sierra Leone. Healthy children and adolescents aged 1–17 years were enrolled in three age cohorts (12–17 years, 4–11 years, and 1–3 years) and randomly assigned (3:1), via computer-generated block randomisation (block size of eight), to receive an intramuscular injection of either Ad26.ZEBOV (5 × 1010 viral particles; first dose) followed by MVA-BN-Filo (1 × 108 infectious units; second dose) on day 57 (Ebola vaccine group), or a single dose of meningococcal quadrivalent (serogroups A, C, W135, and Y) conjugate vaccine (MenACWY; first dose) followed by placebo (second dose) on day 57 (control group). Study team personnel (except for those with primary responsibility for study vaccine preparation), participants, and their parents or guardians were masked to study vaccine allocation. The primary outcome was safety, measured as the occurrence of solicited local and systemic adverse symptoms during 7 days after each vaccination, unsolicited systemic adverse events during 28 days after each vaccination, abnormal laboratory results during the study period, and serious adverse events or immediate reportable events throughout the study period. The secondary outcome was immunogenicity (humoral immune response), measured as the concentration of Ebola virus glycoprotein-specific binding antibodies at 21 days after the second dose. The primary outcome was assessed in all participants who had received at least one dose of study vaccine and had available reactogenicity data, and immunogenicity was assessed in all participants who had received both vaccinations within the protocol-defined time window, had at least one evaluable post-vaccination sample, and had no major protocol deviations that could have influenced the immune response. This study is registered at ClinicalTrials.gov, NCT02509494. Findings—From April 4, 2017, to July 5, 2018, 576 eligible children or adolescents (192 in each of the three age cohorts) were enrolled and randomly assigned. The most common solicited local adverse event during the 7 days after the first and second dose was injection-site pain in all age groups, with frequencies ranging from 0% (none of 48) of children aged 1–3 years after placebo injection to 21% (30 of 144) of children aged 4–11 years after Ad26.ZEBOV vaccination. The most frequently observed solicited systemic adverse event during the 7 days was headache in the 12–17 years and 4–11 years age cohorts after the first and second dose, and pyrexia in the 1–3 years age cohort after the first and second dose. The most frequent unsolicited adverse event after the first and second dose vaccinations was malaria in all age cohorts, irrespective of the vaccine types. Following vaccination with MenACWY, severe thrombocytopaenia was observed in one participant aged 3 years. No other clinically significant laboratory abnormalities were observed in other study participants, and no serious adverse events related to the Ebola vaccine regimen were reported. There were no treatment-related deaths. Ebola virus glycoprotein-specific binding antibody responses at 21 days after the second dose of the Ebola virus vaccine regimen were observed in 131 (98%) of 134 children aged 12–17 years (9929 ELISA units [EU]/mL [95% CI 8172–12 064]), in 119 (99%) of 120 aged 4–11 years (10 212 EU/mL [8419–12 388]), and in 118 (98%) of 121 aged 1–3 years (22 568 EU/mL [18 426–27 642]). Interpretation—The Ad26.ZEBOV and MVA-BN-Filo Ebola vaccine regimen was well tolerated with no safety concerns in children aged 1–17 years, and induced robust humoral immune responses, suggesting suitability of this regimen for Ebola virus disease prophylaxis in children

Safety and long-term immunogenicity of the two-dose heterologous Ad26.ZEBOV and MVA-BN-Filo Ebola vaccine regimen in adults in Sierra Leone: a combined open-label, non-randomised stage 1, and a randomised, double-blind, controlled stage 2 trial

Background The Ebola epidemics in west Africa and the Democratic Republic of the Congo highlight an urgent need for safe and effective vaccines to prevent Ebola virus disease. We aimed to assess the safety and long-term immunogenicity of a two-dose heterologous vaccine regimen, comprising the adenovirus type 26 vector-based vaccine encoding the Ebola virus glycoprotein (Ad26.ZEBOV) and the modified vaccinia Ankara vector-based vaccine, encoding glycoproteins from Ebola virus, Sudan virus, and Marburg virus, and the nucleoprotein from the Tai Forest virus (MVA-BN-Filo), in Sierra Leone, a country previously affected by Ebola. Methods The trial comprised two stages: an open-label, non-randomised stage 1, and a randomised, double-blind, controlled stage 2. The study was done at three clinics in Kambia district, Sierra Leone. In stage 1, healthy adults (aged ≥18 years) residing in or near Kambia district, received an intramuscular injection of Ad26.ZEBOV (5×1010 viral particles) on day 1 (first dose) followed by an intramuscular injection of MVA-BN-Filo (1×108 infectious units) on day 57 (second dose). An Ad26.ZEBOV booster vaccination was offered at 2 years after the first dose to stage 1 participants. The eligibility criteria for adult participants in stage 2 were consistent with stage 1 eligibility criteria. Stage 2 participants were randomly assigned (3:1), by computer-generated block randomisation (block size of eight) via an interactive web-response system, to receive either the Ebola vaccine regimen (Ad26.ZEBOV followed by MVA-BN-Filo) or an intramuscular injection of a single dose of meningococcal quadrivalent (serogroups A, C, W135, and Y) conjugate vaccine (MenACWY; first dose) followed by placebo on day 57 (second dose; control group). Study team personnel, except those with primary responsibility for study vaccine preparation, and participants were masked to study vaccine allocation. The primary outcome was the safety of the Ad26.ZEBOV and MVA-BN-Filo vaccine regimen, which was assessed in all participants who had received at least one dose of study vaccine. Safety was assessed as solicited local and systemic adverse events occurring in the first 7 days after each vaccination, unsolicited adverse events occurring in the first 28 days after each vaccination, and serious adverse events or immediate reportable events occurring up to each participant’s last study visit. Secondary outcomes were to assess Ebola virus glycoprotein-specific binding antibody responses at 21 days after the second vaccine in a per-protocol set of participants (ie, those who had received both vaccinations within the protocol-defined time window, had at least one evaluable post-vaccination sample, and had no major protocol deviations that could have influenced the immune response) and to assess the safety and tolerability of the Ad26.ZEBOV booster vaccination in stage 1 participants who had received the booster dose. This study is registered at ClinicalTrials.gov, NCT02509494. Findings Between Sept 30, 2015, and Oct 19, 2016, 443 participants (43 in stage 1 and 400 in stage 2) were enrolled; 341 participants assigned to receive the Ad26.ZEBOV and MVA-BN-Filo regimen and 102 participants assigned to receive the MenACWY and placebo regimen received at least one dose of study vaccine. Both regimens were well tolerated with no safety concerns. In stage 1, solicited local adverse events (mostly mild or moderate injection-site pain) were reported in 12 (28%) of 43 participants after Ad26.ZEBOV vaccination and in six (14%) participants after MVA-BN-Filo vaccination. In stage 2, solicited local adverse events were reported in 51 (17%) of 298 participants after Ad26.ZEBOV vaccination, in 58 (24%) of 246 after MVA-BN-Filo vaccination, in 17 (17%) of 102 after MenACWY vaccination, and in eight (9%) of 86 after placebo injection. In stage 1, solicited systemic adverse events were reported in 18 (42%) of 43 participants after Ad26.ZEBOV vaccination and in 17 (40%) after MVA-BN-Filo vaccination. In stage 2, solicited systemic adverse events were reported in 161 (54%) of 298 participants after Ad26.ZEBOV vaccination, in 107 (43%) of 246 after MVA-BN-Filo vaccination, in 51 (50%) of 102 after MenACWY vaccination, and in 39 (45%) of 86 after placebo injection. Solicited systemic adverse events in both stage 1 and 2 participants included mostly mild or moderate headache, myalgia, fatigue, and arthralgia. The most frequent unsolicited adverse event after the first dose was headache in stage 1 and malaria in stage 2. Malaria was the most frequent unsolicited adverse event after the second dose in both stage 1 and 2. No serious adverse event was considered related to the study vaccine, and no immediate reportable events were observed. In stage 1, the safety profile after the booster vaccination was not notably different to that observed after the first dose. Vaccine-induced humoral immune responses were observed in 41 (98%) of 42 stage 1 participants (geometric mean binding antibody concentration 4784 ELISA units [EU]/mL [95% CI 3736–6125]) and in 176 (98%) of 179 stage 2 participants (3810 EU/mL [3312–4383]) at 21 days after the second vaccination. Interpretation The Ad26.ZEBOV and MVA-BN-Filo vaccine regimen was well tolerated and immunogenic, with persistent humoral immune responses. These data support the use of this vaccine regimen for Ebola virus disease prophylaxis in adults

Analysis of CO₂ separation unit integration with the thermal-steam cycle of the power unit

Światowe tendencje w ochronie środowiska wskazują na konieczność ograniczenia emisji dwutlenku węgla, który wpływa na rozwój efektu cieplarnianego. Ponieważ podstawowym paliwem wykorzystywanym w energetyce zawodowej jest węgiel, sektor przemysłu jest największym emitorem CO2; zatem prace nad redukcją dwutlenku węgla w tej branży są w pełni uzasadnione. Wchwili obecnej adsorpcyjne technologie wychwytu CO2 nie są jeszcze zastosowane w skali przemysłowej, tym samym nie posiadamy w pełni udokumentowanych informacji dotyczących ich wpływu na bloki energetyczne. Przy wykorzystaniu oprogramowania IPSEpro zamodelowano obieg referencyjny bloku o mocy 833MWe oraz układ separacji CO2 ze spalin, który bazuje na metodach adsorpcyjnych. Analizowano technologię PTSA (Pressure Temperature Swing Adsorption) stanowiącą połączenie dwóch technologii separacji PSA (Pressure Swing Adsorption) i TSA (Temperature Swing Adsorption). Po opracowaniu układów zintegrowano jednostkę wychwytu dwutlenku węgla i innych urządzeń technologicznych z obiegiem parowo-wodnym elektrowni. Integracja w tym wypadku polega na jak najbardziej optymalnym rozmieszczeniu wszystkich urządzeń niezbędnych separacji i transportu CO2. Dane uzyskane z obliczeń modelowych pozwoliły na dokładną analizę wpływu układu separacji CO2 oraz innych niezbędnych urządzeń potrzebnych do realizacji samego procesu wychwytu CO2 i jego przygotowania do transportu w postaci ciekłej na moc bloku oraz sprawność obiegu. Przeprowadzona analiza pozwoliła na oszacowanie ilości dwutlenku węgla, który nie zostanie wyemitowany do atmosfery, co niewątpliwie może zmniejszyć uciążliwość instalacji energetycznych dla środowiska.Global trends in environmental protection point to the need to reduce emissions of carbon dioxide contributing to the greenhouse effect. Since the primary fuel used in the power industry is coal, the power industry is the largest emitter of CO2, justifying a particular focus on reducing the emissions fromthis source. At present, adsorption technologies for CO2 capture are not yet used on a commercial scale, and there is a lack of adequate information concerning their effects on energy units. IPSEpro software was used for modeling a reference thermal-steam cycle power unit with an 833MWe load, and CO2 separation fromthe flue gas unit (which is based on adsorptionmethods). This study analyzed PTSA (Temperature Pressure Swing Adsorption) technology, which represents a combination of two separation technologies – PSA (Pressure Swing Adsorption) and TSA (Temperature Swing Adsorption). After the development of the systems of the power unit, the carbon dioxide capture unit and other technological installations were integrated into the thermal-steam cycle of the power unit. Integration in this case relied on the optimal arrangement of all the equipment necessary to carry out the task of reducing emissions of carbon dioxide in the steam cycle of the power unit. The data obtained from the model’s calculations allowed for accurate analysis of the impact of the separation of CO2. It was also possible to evaluate other devices needed for the implementation of the process of CO2 capture and preparation for transport in liquid form, considering the unit load and the cycle efficiency. The analysis made it possible to estimate the carbon dioxide amount not emitted into the atmosphere, a key factor in measuring the impact of power plants on the environment

Heat transfer research on enhanced heating surfaces in pool boiling

The paper focuses on the analysis of the enhanced surfaces in such applications as boiling heat transfer. The testing measurement module with enhanced heating surfaces was used for pool boiling research. Pool boiling experiments were conducted with distilled water at atmospheric pressure in the vessel using an enhanced sample as the bottom heating surface. The samples are soldered to a copper heating block of the round cross-section .They were placed: in the fluid (saturation temperature measurement), under the sample for temperature determination. A vessel made of four flat glass panes was used for visualization. The heated surfaces in contact with the fluid differed in roughness were smooth or enhanced. This paper analyzes the effects of the microstructured heated surface on the heat transfer coefficient. The results are presented as relationships between the heat transfer coefficient and the heat flux and as boiling curves. The experimental data obtained for the two types of enhanced heated surfaces was compared with the results recorded for the smooth heated surface. The highest local values of the heat transfer coefficient were reported for the enhanced surfaces

Transitional Phenomena on Phase Change Materials

One of the most significant problem with technology development is transferring of large heat fluxes, which requires constant heat transfer temperature (in the specified temperature range). This problem concern mainly the nuclear energetics, space technologies, military technologies and most of all electronics containing integrated circuits with very large scale of integrations. Intensive heat transfer and thermal energy storage are possible by the use of phase change materials (PCMs). In the paper there are presented preliminary results of research on the use of liquid-gas (L-G PCMs) and solid-solid phase change materials (S-S PCMs). For L-G PCMs the boiling characteristics were determined by increasing and decreasing the heat flux, which for certain sets of structural parameters of the heating surface and the physical properties of the liquid induce a variety of forms of transitional phenomena. Thermal energy storage is much more effective when using PCMs than sensible heat

Transitional Phenomena on Phase Change Materials

One of the most significant problem with technology development is transferring of large heat fluxes, which requires constant heat transfer temperature (in the specified temperature range). This problem concern mainly the nuclear energetics, space technologies, military technologies and most of all electronics containing integrated circuits with very large scale of integrations. Intensive heat transfer and thermal energy storage are possible by the use of phase change materials (PCMs). In the paper there are presented preliminary results of research on the use of liquid-gas (L-G PCMs) and solid-solid phase change materials (S-S PCMs). For L-G PCMs the boiling characteristics were determined by increasing and decreasing the heat flux, which for certain sets of structural parameters of the heating surface and the physical properties of the liquid induce a variety of forms of transitional phenomena. Thermal energy storage is much more effective when using PCMs than sensible heat