Discharge Cleaning Research Articles

Wall conditions in WEST during operations with a new ITER grade, actively cooled divertor

Future fusion reactors like ITER and DEMO will have all-tungsten (W) walls and long pulses. These features will make wall conditioning more difficult than in most of the existing devices. The W Environment Steady-state Tokamak (WEST) is one of the few long pulse (364 s) fusion devices with actively cooled W plasma-facing components in the world. WEST is a unique test bed to study impurity migration and plasma density control via reactor relevant wall conditioning techniques. The phase II of WEST operations began in 2022, after the installation of a new lower divertor, now entirely equipped with actively cooled, ITER grade, W monoblocks. After pump down, we baked WEST between 90 °C and 170 °C for ∼2 weeks. After 82.5 h at 90 °C and 33 h at 170 °C, vacuum conditions were stable with a vessel pressure of 6x10-5 Pa and mass spectra dominated by H2 molecules. While at 170 °C, we performed ∼40 h of D2 glow discharge cleaning (GDC) and ∼5 h of glow discharge boronization (GDB), using a 15 %-85 % B2D6-He mix and a total boron mass of ∼12 g. This was the very first GDB at such high temperature for WEST. The whole wall conditioning sequence led to a ∼10 times reduction of the H2O signal as well as to a ∼3 times reduction of the O2 signal, according to mass spectra. Once back to 70 °C, the vessel pressure was 5.5x10-6 Pa and plasma restart was seamless with ∼30 s cumulated over the very first 5 pulses and an Ohmic radiated power fraction Frad = 0.6, showing successful conditioning of the new ITER grade divertor. The effect of the first, ‘hot’ GDB faded with a characteristic cumulative injected energy of 2.45 GJ and saturation towards Frad ∼0.8. After 1.4 h and 7.5 GJ of cumulative plasma time and injected energy, we carried out a second GDB, this time at 70 °C. This ‘cold’ GDB initially led to a much lower Ohmic Frad = 0.3–0.4 but the effect lasted ∼7 times less, with a characteristic cumulative injected energy of 0.37 GJ. At the end of the campaign, we cumulated ∼3h and ∼30 GJ through repetitive, minute long pulses without any boronization. Throughout this 4-weeks-long experiment, Frad in the 4 MW heating phase evolved only marginally (from 0.5 to 0.55). This increase is mostly due to the build-up of re/co-deposited layers on both lower divertor targets.

Coated boron layers by boronization and a real-time boron coating using an impurity powder dropper in the LHD

In the Large Helical Device (LHD), diborane (B2H6) is used as a standard boron source for boronization, which is assisted by helium glow discharges. In 2019, a new Impurity Powder Dropper (IPD) system was installed and is under evaluation as a real-time wall conditioning technique. In the LHD, which is a large-sized heliotron device, an additional helium (He) glow discharge cleaning (GDC) after boronization was operated for a reduction in hydrogen recycling from the coated boron layers. This operational time of 3 h was determined by spectroscopic data during glow discharges. A flat hydrogen profile is obtained on the top surface of the coated boron on the specimen exposed to boronization. The results suggest a reduction in hydrogen at the top surface by He-GDC. Trapped oxygen in coated boron was obtained by boronization, and the coated boron, which has boron-oxide, on the first wall by B-IPD was also shown. Considering the difference in coating areas between B2H6 boronization and B-IPD operation, it would be most effective to use the IPD and B2H6 boronization coating together for optimized wall conditioning.

Novel differential pumping system with extended sampling range: Design and application in the EAST tokamak

A novel differential pumping system (DPS) with an adjustable sampling rate has been developed and implemented in the Experimental Advanced Superconducting Tokamak (EAST). This system is equipped with a high-resolution quadrupole mass spectrometer (QMS), covering a mass range of 1–16 atomic mass units (AMU), alongside a conventional QMS with a broader range of 1–200 AMU. The DPS features a dynamic pressure sampling capability from 10−2 to 105 Pa, utilizing a gas dosing valve and an angle valve, enabling a wide gas sampling ratio range of 10−9 to 3 × 10−2. The high-resolution QMS (QMG700) is adept at directly quantifying the partial pressures of deuterium and helium within mixtures, while the conventional QMS (RGA200) offers indirect measurement of D2 partial pressures above 2 × 10−5 Pa, complemented by direct wide-range mass analysis. During the EAST tokamak campaigns of 2023 and 2024, the DPS was effectively utilized for glow discharge cleaning (GDC) at a pressure of 3 Pa and ion cyclotron wall conditioning (ICWC) at approximately 3 × 10−3 Pa, accurately distinguishing deuterium pressure from the helium environment in the wide pressure range of vacuum vessel. Moreover, the DPS was successfully employed to trace the vacuum leak location in EAST campaign with a pressure of up to hundreds Pa. This DPS is a key tool for gas ingredient analysis and leak detection in the EAST campaigns, providing a valuable reference for the vacuum operation of future fusion reactors.

Volatile fatty acids production from kitchen waste slurry using anaerobic membrane bioreactor via alkaline fermentation with high salinity: Evaluation on process performance and microbial succession

In this study, a pilot-scale anaerobic membrane bioreactor (AnMBR) was developed to continuously produce volatile fatty acids (VFAs) from kitchen waste slurry under an alkaline condition. The alkaline fermentation effectively suppressed methanogenesis, thus achieving high VFAs production of 60.3 g/L. Acetic acid, propionic acid, and butyric acid accounted for over 95.0 % of the total VFAs. The VFAs yield, productivity, and chemical oxygen demand (COD) recovery efficiency reached 0.5 g/g-CODinfluent, 6.0 kg/m3/d, and 62.8 %, respectively. Moreover, the CODVFAs/CODeffluent ratio exceeded 96.0 %, and the CODVFAs/NH3-N ratio through ammonia distillation reached up to 192.5. The microbial community was reshaped during the alkaline fermentation with increasing salinity. The membrane fouling of the AnMBR was alleviated by chemical cleaning and sludge discharge, and membrane modules displayed a sustained filtration performance. In conclusion, this study demonstrated that high-quality VFAs could be efficiently produced from kitchen waste slurry using an AnMBR process via alkaline fermentation.

High-parameters experimental linear plasma device for fusion wall conditioning studies

In future, HELPD would provide valuable platform for investigating the issue in the W impurity control, towards the wall conditioning requirements in tokamak.The tungsten (W) impurity caused by sputtering of the first wall is considered as an issue influencing the plasma safe operation of EAST, ITER and other future fusion devices. As a supplement to the experiments on the tokamak, the linear plasma device (LPD) serves as an effective divertor simulator for the W impurity control research. This work presents the design and construction of High-parameters Experimental Linear Plasma Device (HELPD) in detail, including its layout and operation parameters. Besides the function of plasma exposure, the target sample could be exchanged in a separate material pretreatment vessel for wall conditioning, such as lithium coating and glow discharge cleaning (GDC) without breaking vacuum conditions. And the preliminary results show that the device could produce a steady state plasma of 1∼10 eV, and its flux could reach 1022 m−2s−1 with 10 kW helicon wave. In the future, HELPD would provide valuable platform for investigating the issue in the W impurity control，towards the wall conditioning requirements in tokamak.

691. Association between Clostridioides difficile Colonization, Rectal Swab NAAT Positivity, and Environmental Contamination

Abstract Background Clostridioides difficile (CD) colonization is common among hospitalized patients. Screening for toxigenic CD (TCD) colonization with rectal swab nucleic acid amplification tests (NAAT) may identify people at risk for CDI and help prevent onward TCD transmission, especially in immunocompromised patients with long hospitalizations. The study objective was to test whether rectal swab NAAT could detect TCD colonized patients and whether NAAT results identify patients that contribute to environmental contamination. Methods This was a prospective cohort study on two BMT/Leukemia units. Stool specimens, rectal swabs, and environmental swabs (bedrail, room sink, keyboard) were collected from patients at admission and weekly and cultured semi-quantitatively for TCD. NAAT (Cepheid) was performed on rectal swabs (eSwabs; Copan Diagnostics). The relationship between stool TCD concentration, NAAT Ct, and a positive environmental culture was evaluated using univariate logistic regression. Bleach was used for daily and terminal discharge cleaning of all rooms. Toxigenicity was determined by detection of tcdA or tcdB by whole genome sequencing (WGS). Results From January 2019 - July 2019, 659 stool specimens and 495 rectal swabs were collected from 384 patients. Specimens from 554 patient-days were cultured and 126 (23%) were positive. Of those, 88 (70%) were TCD. 21 of 987 (2%) environmental swabs were TCD positive; 18 (86%) were from bedrails. Among 61 unique patient calendar days with paired rectal swab NAAT and stool culture results (paired samples), overall sensitivity of rectal swab NAAT to detect toxigenic CD colonization compared to culture was 44%, with 4/16 (25%) of people colonized with > 0 - < 10,000 CFU/g of TCD and 7/9 (78%) with ≥ 10,000 CFU/g TCD (Figure 1). There was no relationship between stool culture or rectal swab NAAT result and risk of a positive environmental swab (Figure 2). Figure 1. Toxigenic C. difficile semi-quantitative culture and rectal swab NAAT on paired patient-day of specimen collection (N=61 patient-days) Figure 2. Toxigenic C. difficile semi-quantitative stool and rectal swab NAAT results and environmental contamination by paired patient-day of specimen collection Conclusion Rectal swab NAAT may not be sufficiently sensitive to screen for TCD colonization that contributes to environmental contamination. Disclosures Erik R. Dubberke, MD, MSPH, Abbott: Advisor/Consultant|AstraZeneca: Advisor/Consultant|Ferring Pharmaceuticals: Advisor/Consultant|Ferring Pharmaceuticals: Grant/Research Support|Merck and Co.: Advisor/Consultant|Pfizer: Advisor/Consultant|Pfizer: Grant/Research Support|Seres Therapeutics: Advisor/Consultant|Summit: Advisor/Consultant|Theriva Biologics: Grant/Research Support

Machine learning algorithm and neural network architecture for optimization of pharmaceutical and drug manufacturing industrial effluent treatment using activated carbon derived from breadfruit (Treculia africana)

In a recent development, attention has shifted to the application of artificial intelligence for the optimization of wastewater treatment processes. This research compared the performances of the machine learning (ML) model: random forest, decision tree, support vector machine, artificial neural network, convolutional neural network, long-short term memory, and multiple linear regressors for optimization in effluent treatment. The training, testing, and validation datasets were obtained via the design of an experiment conducted on the removal of total dissolved solids (TDS) from pharmaceutical effluent. The breadfruit-activated carbon (BFAC) adsorbent was characterized using scanning electron microscopy and X-ray diffraction techniques. The predictive capacity of an ML algorithm, and neural network architecture implemented to optimize the treatment process using statistical metrics. The results showed that MSE ≤ 1.68, MAE ≤ 0.95, and predicted-R2 ≥ 0.9035 were recorded across all ML. The ML output with minimum error functions that satisfied the criterion for clean discharge was adopted. The predicted optimum conditions correspond to BFAC dosage, contact time, particle size, and pH of 2.5 mg/L, 10 min, 0.60 mm, and 6, respectively. The optimum transcends to a reduction in TDS concentration from 450 mg/L to a residual ≤ 40 mg/L and corresponds to 90% removal efficiency, indicating ± 1.01 standard deviation from the actual observation practicable. The findings established the ML model outperformed the neural network architecture and affirmed validation for the optimization of the adsorption treatment in the pharmaceutical effluent domain. Results demonstrated the reliability of the selected ML algorithm and the feasibility of BFAC for use in broad-scale effluent treatment.

Optimization of Wall-Conditioning Techniques on the MT-II Tokamak

The MT-II is a small spherical tokamak that is currently under construction at the Pakistan Tokamak Plasma Research Institute. Wall conditioning of the MT-II vacuum vessel (VV) is an essential step to achieve a good quality vacuum for plasma experiments. This study presents an overview of the wall-conditioning techniques implemented on the MT-II VV, including baking and glow discharge cleaning (GDC). Prior to wall conditioning, the system is checked via a helium leak test machine and residual gas analyzer (RGA) to identify and remove leaks. The VV walls are baked at ~180 °C to get rapid desorption of water vapors and other impurities. After the baking process, the partial pressure of most of the carbon- and oxygen-containing impurities is reduced. In particular, the partial pressure of water vapors is reduced by 93%. Consequently, the total leak and outgassing rate is significantly reduced. To further improve the vacuum condition in the vessel, hydrogen GDC is carried out. The fill hydrogen pressure and anode voltage are optimized to get a stable glow discharge. The RGA scan shows that GDC reduces the partial pressure of H2O, O2, and CO2 by 57%, 63%, and 51%, respectively. The results signify that baking and GDC are effective techniques for wall conditioning of the MT-II VV.

Availability of clean water and discharge reliable for housing taman argo subur cisoka, tangerang district

The problem of water availability is an important issue in the development of a residential area, because the availability of water resources is the supporting capacity for the development of a residential area. Adequate water availability for now and predictions of future water availability are very important to know for ensuring an area that is feasible for development. The purpose of this study is to determine the amount of water availability through the method of calculating the water balance and calculating the mainstay discharge to find out whether the water needs are fulfilled or not. Household water consumption is one of the biggest contributors to the water crisis in residential areas. For this reason, it is necessary to have information that has high accuracy regarding the existence of water sources and the amount of water reserves owned by a location. The water balance is one way to determine the availability of water in an area so that it can be calculated whether the location will experience a water crisis or not. Calculation of water balance using the FJ Mock method can provide the information needed whether an area has a surplus of water or not and can be used to calculate the mainstay discharge which is useful for distributing water to residents. Making reservoirs or tendons is an alternative to overcome the occurrence of a water crisis when the dry season comes because often residential areas experience water shortage problems. For this reason, a calculation is made regarding the amount of water debit produced by the water reservoir made by the manager and the amount of surplus water is based on the monthly average method. The results of the calculation of the FJ Mock discharge can be seen that the resulting maximum discharge is 0.504 m3/second and the minimum discharge is 0.069 m3 / sec. The results of the reliable discharge calculation show that the water discharge is still acceptable or meets the criteria because even though in August the water discharge that was achieved was only 0.069 m3/sec, this amount still meets the requirements at a reliability value of 99% and at an error value of 1%. These results provide evidence that the discharge generated by the two residential tendons of Taman Argo Subur still meets the requirements.

Design of vacuum system for NCST spherical tokamak

The NanChang Spherical Tokamak (NCST) is a new compact tokamak with an aspect ratio of R/a = 1.67. The vacuum system is one of the most important sub-systems of the tokamak device and has been designed especially for the NCST device. It consists of three main parts: a pumping system, a gas puffing system, and a wall conditioning system. The pumping system includes two turbo-molecular pumps, a cryopump, and two rotary pumps. The gas puffing system consists of a gas supply, transfer lines, a gas reservoir, pressure gauges, and piezoelectric valves. The wall conditioning system includes baking and glow discharge cleaning functions. The vacuum system and related experimental results are described in detail in this paper. The test results indicate that the NCST vacuum system is reliable. Inside the vessel, the ultimate pressure reached 4.2 × 10−6 Pa after 307 h of pumping. The upgraded gas puffing system can accurately control the gas entering the vacuum vessel. The wall conditioning systems, such as those for baking and glow discharge cleaning, also play a very important role in plasma operation. The plasma discharge results show that the basic function of the vacuum system meets the essential requirements of the present experiments on the NCST tokamak.

Psychosocial factors predicting symptoms of depression and anxiety in allogeneic hematopoietic stem cell transplant recipients in Japan.

We explored whether a patient's psychosocial background before allogeneic hematopoietic stem cell transplantation (allo-HSCT) could predict the occurrence of psychiatric symptoms during treatment and after hospital discharge. Logistic regression analysis was performed using INTERMED, a scale that comprehensively evaluates psychological factors such as psychiatric history, current mental status, and coping skills, and social factors such as social participation status, relationships with others, and living environment, which were used as independent variables. The Center for Epidemiologic Studies Depression Scale was used to measure depression, while the Profile of Mood States was used to measure anxiety and other symptoms. Both measures were used as dependent variables and were administered upon clean room admission, during clean room stay, at clean room discharge, and at 3, 6, and 12months after hospital discharge. Participants included 70 patients (45 males and 25 females, mean age 53.3 ± 12.3years). Thirty-eight patients participated in the program for the entire period, up to 12months after hospital discharge. The total score on the Japanese version of the INTERMED and psychological factor scores assessed at baseline were significant predictors of depressed mood on discharge; however, there were no significant predictors of scores on the Profile of Mood States. A comprehensive pretransplant evaluation of psychosocial background can help predict the appearance of psychiatric symptoms after allo-HSCT. In patients who are expected to develop psychiatric symptoms after allo-HSCT, it is important to consider early intervention by a specialist and close monitoring by a medical team.

Nanostructured Iron Oxides: Structural, Optical, Magnetic, and Adsorption Characteristics for Cleaning Industrial Effluents

Globally, efforts are being made to upgrade and improvise the current wastewater treatment technologies. Industrial wastewater is being generated exponentially, owing to the expansion in chemical industries and civilizations necessitating remediation to prevent further environmental damage and lower associated human risks. In this work, iron oxide nanoparticles (IONPs) have been developed and employed as an efficient nanocatalyst for heavy metal adsorption via the chemical route. The shape, absorbance optical, crystal phase, and magnetization of as-prepared magnetic nanostructures were characterized using XRD (X-ray diffraction), UV-Vis (ultraviolet-visible), HRTEM (High-resolution transmission electron microscopy), FTIR (Fourier transfer infrared spectroscopy), and VSM. Further, the adsorption ability of iron oxide to remove the bulk metallic elements considering cadmium (Cd), lead (Pb), zinc (Zn), chromium (Cr), copper (Cu), and nickel (Ni), present in industrial effluents, were studied. The Maghemite Fe2O3 crystal phase having an R-3c group is observed in the XRD results. An identical shape of spherical nanostructures is determined using TEM including ≈21 nm for pure Fe2O3. A removal % was studied by using ICP-OES, and showed a Cr (61.2%), Cd (98%), Cu (66%), Ni (64%), Zn (97%), and Pb (98%) removal ability. The application of such monitored nanomaterials to effluent cleaning and sewage discharge emitted via labs and petrochemical industries could be expanded.

Machine learning model for the optimization and kinetics of petroleum industry effluent treatment using aluminum sulfate

Small-scale preliminary studies are necessary to determine the feasibility of the machine learning (ML) algorithm and time-evolution kinetics to meet the design specification of the treatment unit. The train and test datasets were obtained from jar test experimentation on the petroleum industry effluent (PIE) sample using aluminum sulfate (AS) as the coagulant. The ML algorithm from scikit-learn was employed to determine the optimum operating condition for the removal of colloidal particles, causing turbidity in the PIE. The predictive capacity of four ML models was compared based on their statistical metrics for clean discharge. The predicted optimum condition corresponds to pH (10), dosage (0.1 g/L), and settling time (30 min) which transcends to residual turbidity ≤ 10 NTU and translates to 95% removal efficiency. The second-order AS-sweep flocculation kinetic showed that at the predicted optimum conditions, modeled rate constant of 1.33 × 10−3 L/g.min and flocculation period of 1.2 min reduced the combination of the monomer, dimmer, and trimmer class colloids from an initial 570 mg/L concentration to the residual counts of 24 mg/L corresponding to residual turbidity ≤ 10 NTU under the mixing regime 14 s−1 ≤ G ≤ 164 s−1 satisfied the EPA standard for clean effluent discharge. It incorporated the selected ML output with time-evolution and aggregation kinetics to define sedimentation tank geometry for cleaner discharge. The findings from the design-driven optimization recommended a flow rate (1000 m3s−1), coefficient of kinematic viscosity (0.841 mm/s), and the required detention time (30–60 min) to define the sedimentation tank geometry.

The Treatment Effect of Chemical Coagulation Process in South African Brewery Wastewater: Comparison of Polyamine and Aluminum-Chlorohydrate coagulants

An evaluation of a laboratory scale chemical coagulation using aluminium chlorohydrate (1%) and polyamine (1%) coagulants on its effectiveness in the removal of bulk inert pollutant contents such as particulate chemical oxygen demand (COD) and turbidity to obtain clean effluent discharge and most cost-effectively treated effluent using a jar test was conducted in this current study. This study aimed to find the viable inert removal coagulant between the two above-mentioned coagulants in order to achieve zero liquid effluent discharge (ZLED). The preliminary results showed that adding variable dosages of polyamine and 50% aluminium chlorohydrate combined coagulants dosages presented an improved particulate chemical oxygen demand, color, and turbidity removal efficiencies. The ascertained turbidity removal efficiency using the combined coagulation dosage of polyamine–aluminium chlorohydrate (PAC) treatment was 90.50% and 59.36% particulate chemcial oxygen demand removal, as comparable to polyamine alone with particulate chemical oxygen demand removal of 50% and turbidity of 75%. Likewise, an appreciable removal efficacy was observed as the aluminium chlorohydrate treatment alone was for particulate chemical oxygen demand and turbidity was 37% and 54%, respectively. In essence, this study emphasized the knowledge gap of the significant effect of the polymeric polyamine flocculant strength in adopting the combined coagulation dosage method to improve its coagulation efficiency and the high agglomeration on suspended solids, thereby, removing more of the unwanted inert contents from brewery wastewater. To determine zero liquid effluent discharge, this study clearly recommended an integrated treatment approach, microbial fuel cell integrated with a lab scale chemical coagulation technique for efficient non-biodegradable pollutant removal.

ANALYSIS OF CLEAN WATER NEEDS IN RANOKOMEA VILLAGE, WEST POLEANG DISTRICT, BOMBANA REGENCY

The background of this research is the clean water in the village of Rakomea, which is inadequate because the amount of clean water discharge is not evenly distributed to all residential residents. This study aims to determine the clean water needs of the Ranokomea village community, West Poleang district, Bombana regency, in 2020 and the projected the year 2025. This research uses a quantitative descriptive research method with a sample of 81 family heads. The results showed that the needs for the net water of the people of Ranokomea village were 63,037 litres/person/day, and clean water needs in the year of 2025 projection namely 63.03 litres/person/day. Based on the feasibility standards of clean water needs issued by the UNESCO World Agency, namely 60 litres/person/day then, the needs of the people of Ranokomea village are not fulfilled because in 2020, people′s clean water needed 57.11 litres/person/day and in the year of 2025 projection namely 63.03 litres/person/day.

Overview of recent experimental results from the ADITYA-U tokamak

Since the 2018 IAEA-FEC conference, in addition to expanding the parameter horizons of the ADITYA-U machine, emphasis has been given to dedicated experiments on inductively driven particle injection (IPI) for disruption studies, runaway electron (RE) dynamics and mitigation, plasma rotation reversal, radiative-improved modes using Ne and Ar injection, modulation of magneto–hydrodynamic modes, edge turbulence using periodic gas puffs and electrode biasing (E-B). Plasma parameters close to the design parameters of circular plasmas with H2 and D2 as fuel have been realized, and the shaped plasma operation has also been initiated. Consistent plasma discharges having I P ∼ 100–210 kA, t ∼ 300–400 ms, n e ∼ 3–6 × 1019 m−3, core T e ∼ 300–500 eV were achieved with a maximum B T of ∼1.5 T. The enhanced plasma parameters are the outcome of repeated cycles of baking (135 °C), followed by extensive wall conditioning, which includes pulsed glow discharge cleaning in H, He and Ar–H mixture, and lithiumization. A higher confinement time has been observed in D2 compared to H2 plasmas. Furthermore, shaped plasmas are attempted for the first time in ADITYA-U. A first of its kind inductively driven particle injection for disruption mitigation studies has been developed and operated. The injection of solid particles into the plasma core leads to a fast current quench. Two pulses of electron cyclotron resonance wave at 42 GHz are launched in a single discharge: one pulse is used for pre-ionization and the second for heating. In a novel approach, a positively biased electrode is used to confine REs after discharge termination. E-B is also used for controlling the rotation of drift-tearing modes by changing the plasma rotation. Cold pulse propagation and signatures of detachment are observed during the injection of short gas puffs. A correlation between the plasma toroidal rotation and the total radiated power has been observed with neon gas injection-induced improved confinement modes.

Analisis Kebutuhan Debit Air Di Gedung C RSUD Kota Bukittinggi

In the Bukittinggi City Hospital building which has 6 floors, there is a water pump and a reservoir used to supply clean water for daily needs. Based on the reality in the field where there is no secondary data to determine the type of pump and reservoir. The purpose of this analysis is to obtain clean water discharge requirements, obtain the type of pump and ensure that the reservoir used for building C RSUD Kota Bukittinggi is in accordance with the type of pipe and reservoir installed in building C, floor 6. By using field studies and interviews and applying the formulas related to pump calculations. In determining the type of pump to be used in the building, it includes the required water discharge, determining the capacity of the components to be used such as pipe diameter, water tank capacity on the ground floor and roof of the building and the total head on the pipe. Based on the calculation results, the required water discharge is 0.08333 m 3 /min, the upper reservoir has a capacity of 150,000 liters, the bottom reservoir is 5,000 liters and the Hot that occurs is 18.429 m. Then the required pump specifications are 40 x 32B2 -51.5 Grundfos CM 10-3. The pump specifications are not much different from those that have been applied in the field.

Lithium wall conditioning techniques in ADITYA-U tokamak for impurity and fuel control

In fusion devices, various techniques are employed for coating the plasma facing components (PFCs) including the vessel wall with low-Z material like lithium, boron, and silicon in order to enhance the plasma parameters and control. In ADITYA-Upgrade tokamak, different techniques of lithium wall conditioning are developed and implemented to obtain uniform and sustainable coating of Li on PFCs and the vessel wall. In this paper, two techniques used to generate Li from the source are reported. In one of the technique, a heated (fixed temperature of ∼120 °C) Li-rod is placed inside the hydrogen glow discharge cleaning (H-GDC) plasma and the sputtered Li by hydrogen (H) ions and atoms coats the wall and periphery. In the second technique, the Li is vapourized using a high-temperature Li-evaporator and released into the H-GDC plasma for uniform coating of Li on the PFCs and vessel. Significantly enhanced plasma parameters are obtained after Li coating by both techniques, with the evaporated Li performed better than the Li rod case. With the Li coating obtained with evaporated Li at 600 °C (550 mg Li) with H-GDC, the Li wall conditioning has been observed to be sustaining for in a larger number of plasma discharges in comparison to non-H-GDC assisted Li deposition. As the melting temperature of lithium hydride (LiH) is much higher (688.7 °C) than that of lithium (180.5 °C), this enhance the longer Li-coating lifetime relatively due to the formation of Li–H molecules on the vessel wall and PFCs. In ADITYA-U the carbon impurity and hydrogen recycling, due to relatively high surface area of graphite PFCs as well as their proximity to the plasma, limits the plasma performance and effective controls. Hence, H-GDC, H-GDC with Li-rod sputtering or Li evaporation, helium-GDC, argon–hydrogen mixtures-GDC in particular sequence are carried out to obtain better plasma discharges. The Li coating techniques and their effect on tokamak plasma discharges of ADITYA-U are discussed in this paper.

PERENCANAAN SISTEM AIR BERSIH PADA PEMBANGUNAN TOWER PREMIER APARTEMEN BESS MANSION SURABAYA

Plumbing installation system must be well planned, especially for high rise building. Clean water and waste water networks planning in the Tower Premier BeSS Mansion Surabaya Apartment are designed to serve the occupants needs of clean water. BeSS Mansion Apartement is a high-rise building with ± 86.000 m2area, consist of 3 towers named : Premier Tower and Suite Tower, which have area of 51.700 m2and consist of 44 floors, and Podium Tower which has 34.300 m2 area and consist of 1 semi basement and 9 parking floors. Clean water need is calculated based on the number of occupants and the type of room, which require total clean water discharge of 772.8 m³/day. The pipe diameters of clean water system is designed using 4 inches for main pipes and ¾ inch to 1½ inches for distribution pipes. The ground water tank capacity is 257.6 m³ using two tanks which have a capacity of 144 m³ and 128 m³, while the roof tank has a capacity of 51.52 m³.

SIMS and HR-XPS characterization of lithiated graphite from the magnetic fusion device RFX-mod

Lithium wall conditioning has improved the performance of many magnetic fusion devices. Li conditioning in the RFX-mod device was performed by: (1) a single Li pellet injector and (2) a multi-Li pellet injector during He plasma discharges; (3) a Li evaporator after He glow discharge cleaning and He plasma discharge exposure. This report compares the spatial and depth distributions of Li deposited on polycrystalline graphite witness samples at different locations in RFX-mod and the elemental and chemical compositions of the resulting surfaces. The sample surfaces were analyzed ex situ using secondary ion mass spectrometry (SIMS) and high-resolution X-ray photoelectron spectroscopy (HR-XPS). The results showed that Li pellet injection provided a relatively uniform toroidal coverage while Li evaporation produced highly localized Li deposition. A Li 1s HR-XPS peak at 56.5 eV binding energy (BE) characteristic of lithium-intercalated graphite was only observed with the sample exposed to Li evaporation. All of the samples exhibited a HR-XPS C 1s peak at 285.1–285.2 eV BE that is largely attributed to hydrogenated graphite. This finding suggests that hydrogenation of fresh graphite occurs during He plasma discharge exposures. Our results have implications for density control and the selection of Li conditioning techniques in magnetic fusion devices.