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This study examines the impact of industrial activities in Bontang City, a major center for natural gas processing and fertilizer production, which potentially increases heavy metal contamination in coastal waters. Specifically, the research focuses on the accumulation of lead (Pb) and copper (Cu) in Anadara granosa, a benthic bivalve selected as a bioindicator due to its capacity to accumulate pollutants. The study aims to analyze Pb and Cu concentrations in Anadara granosa tissues collected from the waters of Selangan Hamlet, Bontang City, as an indicator of local environmental quality. The research was conducted over a six-month period, involving shellfish and water sampling from four observation stations. Heavy metal analysis was performed using Atomic Absorption Spectrophotometry, and the results were evaluated against relevant environmental quality standards, including Government Regulation of the Republic of Indonesia Number 22 of 2021. The findings revealed the presence of Pb and Cu at all sampling stations, with varying concentrations. The highest Pb and Cu levels were recorded at the South Station, while the lowest concentrations were observed at the East and North Stations. Overall, the measured concentrations of both metals significantly exceeded established safety limits, indicating serious risks to aquatic ecosystems and human health. These results confirm Anadara granosa as an effective bioindicator of heavy metal pollution and highlight the urgent need for further studies and mitigation efforts.

The decline in the performance of the die casting machine in 1998 after a long period of producing copper terminals showed dimensional defects and instability in product quality, especially in nozzle clogging, reduced copper flow, crust buildup on the gooseneck, plunger movement obstruction, and hydraulic pressure leaks. The purpose of planning the replacement and repair of die-casting machine components is to obtain replacement and repair costs, replacement and repair schedules for the period 2026, and the ratio of maintenance costs to profits. The replacement and repair planning method includes collecting previous maintenance data, applying the inspection-replace-repair-overhaul (IRRO) method, evaluating component conditions, predicting component service life, predicting labor costs, predicting supporting equipment to be used in maintenance, predicting the time to replace spare parts or reinstall repaired components, estimating replacement and repair costs for the period 2026, and calculating the ratio of replacement and repair costs to profits. The planning results obtained replacement and repair costs for the 2026 period are 75.770.000,- IDR with an estimated die casting machine rental rate of  1,500,000 IDR/hour which has the potential to be rented for 1,200 hours/year, and the ratio of maintenance costs to profits is 10,02 % which implies that the die casting machine with a capacity of 40 units/hour is still suitable for use and has the prospect of generating profits for the next few years.

This research focuses on the synthesis and characterization of the double salt copper(II) ammonium sulfate hexahydrate, Cu(NH4)2(SO4)2·6H2O. The study aims to obtain the compound in crystalline form and evaluate its properties through yield calculation, solubility testing, and Fourier Transform Infrared (FTIR) spectroscopy. The synthesis involved reacting copper(II) sulfate pentahydrate (CuSO4·5H2O) with ammonium sulfate ((NH4)2SO4) under controlled conditions, followed by crystallization. The process produced 10.84 grams of crystalline Cu(NH4)2(SO4)2·6H2O with an 86.23% yield, indicating efficient synthesis. Solubility tests showed that the crystals were polar, soluble in polar solvents like water and hydrochloric acid (HCl), partially soluble in ammonium hydroxide (NH4OH), and insoluble in less polar solvents like ethanol and chloroform (CHCl3). FTIR analysis confirmed the presence of functional groups such as O–H, N–H, and S–O stretching vibrations, supporting the proposed molecular structure. The findings demonstrate that Cu(NH4)2(SO4)2·6H2O can be efficiently synthesized, and its physicochemical properties align with theoretical expectations. This study contributes to the understanding of double salt synthesis and characterization, relevant for inorganic chemistry, material science, and potential applications in catalysis and coordination chemistry.

Trace elements such as copper, zinc, selenium, and chromium play essential roles in various enzymatic reactions, antioxidant defense mechanisms, and overall metabolic regulation, making them crucial for maternal and fetal health. During pregnancy, the demand for these micronutrients increases significantly due to physiological changes and the needs of the developing fetus. Inadequate or excessive levels of these trace elements can lead to altered fetal development and may impact neonatal outcomes immediately after birth. Given the sensitive developmental window of gestation, the intrauterine environment—including micronutrient status—has been hypothesized to influence neonatal physiological parameters such as heart rate, respiratory rate, and Apgar scores, which are commonly used to assess neonatal wellbeing in the early minutes of life. This study attempts to explore the impact of maternal trace element status—specifically copper, zinc, selenium, and chromium—along with selected maternal parameters (BMI, parity, gravida) on indicators of neonatal wellbeing, including heart rate, respiratory rate, and 5-minute Apgar score. A cross-sectional study was conducted in the Delivery Room of the Obstetric Hospital in Al-Diwaniya City, Iraq, involving 50 mother-infant pairs. Data collection occurred from December 1, 2024, to February 10, 2025. Maternal blood samples were analyzed using atomic absorption spectrophotometry to determine serum concentrations of copper, zinc, selenium, and chromium. Neonatal outcomes were assessed via standard clinical evaluations: heart rate and respiratory rate were measured immediately postpartum, and Apgar scores were recorded at five minutes. Statistical analyses included Pearson correlation and multiple linear regression to assess associations between maternal factors and neonatal outcomes. Bivariate and multivariate analyses indicated limited but noteworthy associations. Maternal serum chromium levels were significantly associated with increased neonatal respiratory rate (p = 0.026), suggesting a possible stimulatory or stress-related effect.

UD. Indokarya Brass is a company engaged in the brass handicraft industry with its main products being door handles and bells. The main raw materials used in the production process include brass, copper, tin, and aluminum, which are obtained from suppliers both within and outside the city. On average, raw materials are received weekly with quantities of 50–100 kg of brass, 7–10 kg of copper, 10–15 kg of tin, and 3–5 kg of aluminum. In addition, the company also uses additional materials in the form of thinner and epoxy purchased from nearby hardware stores with less frequent purchases, namely 5–10 liters of thinner every month and around 5 kg of epoxy every two months. To date, the company has not had a structured policy for procurement and control of raw material inventory. This condition results in excess inventory of several types of raw materials which actually incurs high costs, both in terms of storage costs and warehouse maintenance costs. This excess inventory ultimately has an impact on reduced efficiency and decreased company profits. This study was conducted to analyze the existing inventory system and compare the company's current policy with a proposed method for more optimal inventory control. The calculation results show that the proposed method is able to provide significant inventory cost savings, namely 83.25% in brass raw materials, 15.28% in copper, 14.6% in tin, 43.37% in aluminum, 4.66% in epoxy, 4.2% in thinner, and 40.7% in other raw materials. Thus, the implementation of the right inventory control method can improve operational efficiency and help companies reduce cost burdens, so that profits can be more optimal.

In response to increasing competition in the manufacturing sector, PT X—a copper busbar manufacturing company—implemented Lean Manufacturing supported by Value Stream Mapping (VSM) to improve production efficiency and reduce supply chain costs. This study utilizes VSM, Value Stream Analysis Tools (VALSAT), and Root Cause Analysis (5 Whys) to identify sources of waste and formulate improvement strategies. The analysis identified three dominant wastes: waiting time, product defects, and excess inventory. These were mainly caused by the lack of standardized material procedures, inadequate supporting equipment, and poor integration between the incoming inspection process and the Enterprise Resource Planning (ERP) system. To address these issues, the study proposes installing silica rolls, providing air wipers and flatness tools, developing standardized work instructions, and integrating Internet of Things (IoT) technology with the ERP system for real-time monitoring. As a result of implementing these solutions, PT X successfully reduced its defect rate from 6.23% to 1.32%, decreased lead time, and achieved notable savings in supply chain costs. The findings demonstrate that integrating Lean Manufacturing principles with VSM can effectively eliminate non-value-added activities, streamline production processes, and enhance overall competitiveness. This study reinforces the strategic value of Lean tools in continuous improvement initiatives within the manufacturing industry.

Adding too many electrical components to a vehicle can cause a lack of electrical energy. To overcome this, the capacity of the charging system needs to be improved. One method is by changing the diameter and number of turns of the copper wire in the stator coil. This study tested various combinations of wire diameter and turns to examine their effects on the voltage and temperature produced by the stator coil. The test used wire diameters of 0.7 mm, 0.9 mm, and 1.1 mm, with 50, 60, and 70 turns, at a constant engine speed of 3000 RPM for 5 minutes. The lowest voltage was recorded with a 0.7 mm diameter and 50 turns 26.5 V at the start and 25.7 V at the end. The highest voltage came from the 1.1 mm diameter with 70 turns 51 V at the start and 48.6 V at the end. The starting temperature for all variations was 36 °C. The lowest end temperature was 47.3 °C (0.7 mm, 50 turns), and the highest was 48.8 °C (1.1 mm, 70 turns). The results show that increasing both diameter and the number of turns raises voltage output, while temperature also increases slightly.

Using a descriptive method with a triangulation approach including observation, document analysis, and interviews this study ensures data reliability. Daily monitoring is conducted on wastewater flow and pH levels, while monthly laboratory analysis covers eight key parameters: Total Suspended Solids (TSS), iron (Fe), copper (Cu), zinc (Zn), total chromium (Cr), phosphate (PO³), oil and grease, and pH to evaluate the perfomance of the treatment system. The treatment process begins with the inflow of 960 m³ of wastewater per day into the storage pond, where aeration is applied to ensure homogenization before being transferred to the neutralization unit. pH adjustment is carried out by adding NaOH or HCl before the wastewater undergoes coagulation and flocculation stages. The study’s findings indicate that the WWTP meets the environmental quality standards established in accordance with the Decree of the Head of the Investment Coordinating Board of the Republic of Indonesia (2020), Number SK.214/1/KLHK/2020 concerning the Permit for Wastewater Disposal into the Sea on Behalf of PT Pembangkit Jawa Bali Unit Pembangkitan Gresik. This study emphasizes the importance of systematic monitoring and treatment in wastewater management.

Afghanistan, often called a "geological treasure trove," is richly endowed with vast mineral deposits worth over $3 trillion. The minerals, including copper, lithium, iron, gold, and rare earths, can be used to resurrect the nation's economy, reduce dependence on foreign aid, and bring about political stability. However, three decades of conflict, political turmoil, corruption, and inadequate infrastructure have been a hindrance to the effective exploitation of the resources. This paper examines the role of mining in Afghanistan's economic and political development, distilling the opportunities and challenges in the industry. Drawing on comparative case studies from resource-rich countries like Botswana and Chile, the study highlights the importance of open government, robust regulatory institutions, and strategic foreign partnerships. The evidence suggests that an efficiently operated mining sector would be a driver of sustainable development, provided that Afghanistan addresses deep-seated systemic evils in the form of corruption, insecurity, and environmental degradation. The research concludes with policy imperatives aimed at maximizing the contribution of the sector to national development.

In the curcumin compound there are aromatic compounds that have electronic spins on each side of the benzene. In previous research, the concentration of curcumin and H2O as coatings on copper coils could provide physical changes to the characteristics of copper coils, namely increasing the strength of the magnetic field and increasing the electric current in the coil. The fuzzification process can be described using membership variables with concentrations of curcumin and H2O as input, magnetic field strength and current as output. It is known that the greatest concentration of curcumin indicates increased magnetic field strength and electric current. Simulation of the aromatic spin on the curcumin compound as an Op Amp shows that the highest curcumin concentration value results in an increase in the output voltage (Vout).