Synthesis of S-glycosides analogues containing Thiouracil unite and Evaluated as antibacterial and Antifungal active

Preparation of new S-glycosides including thiouracil derivatives as heterobase. The main step of this work is the formation of thiouracil derivatives [1-3] by the condensation reaction of ethyl cyanoacetate, aromatic aldehydes and thiourea to form target compounds [1-3], after protection of the hydroxyl groups in sugar (D-fructose, L- sorbose, and D-galactose), react with hydrobromic acid 45% in glacial acetic acid give different Bromo sugars [a-c], which coupled with prepares thiouracil derivatives [1-3] and propylthiouracil [4] in the presence of K2CO3 to afford the corresponding product S-glycoside analogs [1-4a, 1-4b, 1-4c]. deprotection of the S-glycoside analogs in acid and base medium, led to the free S-glycoside derivatives [1-4d,1-4e,1-4f]. The obtained compounds were tested for their antibacterial and antifungal actives.

ANALISIS PENGENDALIAN PERSEDIAAN AUX RAW MATERIAL MENGGUNAKAN METODE MIN-MAX STOCK DI PT. MITSUBISHI CHEMICAL INDONESIA

PT. Mitsubishi Chemical Indonesia merupakan perusahaan yang bergerak di bidang industri polyester yang memproduksi Purified Terephthalic Acid (PTA) terbesar di Indonesia. PTA adalah suatu senyawa yang tidak tersedia di alam yang dibuat dari sintesa kimia. Terdapat auxiliary raw material yang diperlukan untuk membantu proses produksi PTA agar dapat berjalan dengan lancar, seperti Hydrobromic Acid (HBr) dan Soda Ash Dense (Na2CO3). Perusahaan belum memiliki jumlah safety stock padahal perusahaan harus mengendalikan persediaan auxiliary raw material agar dapat menghindari kekurangan dan kelebihan bahan baku yang menyebabkan perusahaan dapat mengeluarkan biaya lebih banyak. Hasil perhitungan memperlihatkan bahwa metode min-max stock menunjukan jumlah safety stock bahan baku Hydrobromic Acid yaitu sebesar 17,5 ton dan untuk Soda Ash Dense yaitu sebesar 5,41 ton. Penentuan jumlah persediaan antara kebijakan perusahaan dengan hasil perhitungan metode min-max stock memiliki beberapa perbedaan. Dari perbedaan tersebut, perusahaan dapat menghemat total biaya persediaan sebesar Rp 7.550.000,00 untuk Hydrobromic Acid dan Rp 11.221.224,16 untuk Soda Ash. Frekuensi pemesanan yang terlalu sering dengan ukuran pemesanan yang besar menyebabkan total biaya persediaan menjadi tinggi. Dari hasil tersebut perusahaan perlu menerapkan metode min-max stock untuk mengendalikan persediaan bahan baku supaya dapat menghemat biaya pengeluaran. Abstract[Inventory Control Analysis of Aux Raw Material Using Min-Max Stock Method in Mitsubishi Chemical Indonesia Company] Mitsubishi Chemical Indonesia is a company engaged in the polyester industry that produces the largest Purified Terephthalic Acid (PTA) in Indonesia. PTA is a compound that is not available in nature, so it is made by chemical synthesis. There are auxiliary raw materials that are needed to help the PTA production process, so it can run well, such as Hydrobromic Acid (HBr) and Soda Ash Dense (Na2CO3). The company don’t have the safety stock even though the company should control the aux raw material inventory to avoid the company to run out of stock or overstock, that causes the company to spend a lot of money. The calculations result shows that the amount of the safety stock for Hydrobromic Acid is 17.5 tons and for Soda Ash is 5.41 tons. The determined number of inventories between company policy and the calculation of the min-max stock method have several differences. From those differences, the company can save the total inventory cost amounted at IDR 7.550.000,00 for Hydrobromic Acid and IDR 11.221.224,16 for Soda Ash. High frequency of orders with a large order size can cause the total inventory cost to be high. From that result, the company needs to apply a min-max stock to control inventory and to save money on expenses.Keywords: inventory; min-max stock method; out of stock; overstock; TIC

Recycling Lithium from Waste Lithium Bromide to Produce Lithium Hydroxide

Lithium resources face risks of shortages owing to the rapid development of the lithium industry. This makes the efficient production and recycling of lithium an issue that should be addressed immediately. Lithium bromide is widely used as a water-absorbent material, a humidity regulator, and an absorption refrigerant in the industry. However, there are few studies on the recovery of lithium from lithium bromide after disposal. In this paper, a bipolar membrane electrodialysis (BMED) process is proposed to convert waste lithium bromide into lithium hydroxide, with the generation of valuable hydrobromic acid as a by-product. The effects of the current density, the feed salt concentration, and the initial salt chamber volume on the performance of the BMED process were studied. When the reaction conditions were optimized, it was concluded that an initial salt chamber volume of 200 mL and a salt concentration of 0.3 mol/L provided the maximum benefit. A high current density leads to high energy consumption but with high current efficiency; therefore, the optimum current density was identified as 30 mA/cm2. Under the optimized conditions, the total economic cost of the BMED process was calculated as 2.243 USD·kg−1LiOH. As well as solving the problem of recycling waste lithium bromide, the process also represents a novel production methodology for lithium hydroxide. Given the prices of lithium hydroxide and hydrobromic acid, the process is both environmentally friendly and economical.

Atmospheric gaseous hydrochloric and hydrobromic acid in urban Beijing, China: detection, source identification and potential atmospheric impacts

Gaseous hydrochloric (HCl) and hydrobromic acid (HBr) are vital halogen species that play essential roles in tropospheric physicochemical processes. Yet, the majority of the current studies on these halogen species were conducted in marine or coastal areas. Detection and source identification of HCl and HBr in inland urban areas remain scarce, thus limiting the full understanding of halogen chemistry and potential atmospheric impacts in the environments with limited influence from the marine sources. Here, both gaseous HCl and HBr were concurrently measured in urban Beijing, China, during winter and early spring of 2019. We observed significant HCl and HBr concentrations ranging from a minimum value at 1 × 108 molecules cm−3 (4 ppt) and 4 × 107 molecules cm−3 (1 ppt) up to 6 × 109 molecules cm−3 (222 ppt) and 1 × 109 molecules cm−3 (37 ppt), respectively. The HCl and HBr concentrations are enhanced along with the increase of atmospheric temperature, UVB and levels of gaseous HNO3. Based on the air mass analysis and high correlations of HCl and HBr with the burning indicators (HCN and HCNO), gaseous HCl and HBr are found to be related to anthropogenic burning aerosols. The gas–particle partitioning may also play a dominant role in the elevated daytime HCl and HBr. During the daytime, the reactions of HCl and HBr with OH radicals lead to significant production of atomic Cl and Br, up to 2 × 104 molecules cm−3 s−1 and 8 × 104 molecules cm−3 s−1, respectively. The production rate of atomic Br (via HBr + OH) is 2–3 times higher than that of atomic Cl (via HCl + OH), highlighting the potential importance of bromine chemistry in the urban area. On polluted days, the production rates of atomic Cl and Br are faster than those on clean days. Furthermore, our observations of elevated HCl and HBr may suggest an important recycling pathway of halogen species in inland megacities and may provide a plausible explanation for the widespread halogen chemistry, which could affect the atmospheric oxidation in China.

Atmospheric gaseous hydrochloric and hydrobromic acid in urban Beijing, China: detection, source identification and potential atmospheric impacts

<p>Gaseous hydrochloric (HCl) and hydrobromic acid (HBr) are vital halogen species that play essential roles in tropospheric physicochemical processes. Yet, majority of the current studies on these halogen species were conducted in marine or coastal areas. Detection and source identification of HCl and HBr in inland urban areas (especially megacities) remain scarce, thus, limiting the full understanding of halogen chemistry and potential atmospheric impacts in the environments with limited influence from the marine sources. Here, both gaseous HCl and HBr were concurrently measured by Chemical Ionization-Atmospheric Pressure interface-Long Time Of Flight-Mass Spectrometer (CI-APi-LTOF-MS) in urban Beijing, China at the BUCT station (39.94° N, 116.30° E) during winter and early spring of 2019. We observed significant HCl and HBr concentrations ranged from a minimum value at 1.3×10<sup>8</sup> cm<sup>-3</sup> and 4.3×10<sup>7</sup> cm<sup>-3 </sup>up to 5.9×10<sup>9</sup> cm<sup>-3</sup> and 1.2×10<sup>9</sup> cm<sup>-3</sup>, respectively. The HCl and HBr concentrations are enhanced along with the increase of atmospheric temperature, UVB, and levels of gaseous HNO<sub>3</sub>. Based on the air mass analysis and high correlations of HCl and HBr with the burning indicators (HCN and HCNO), the gaseous HCl and HBr are found to be related to anthropogenic burning aerosols. The gas-aerosol partitioning may also play a dominant role in the elevated daytime HCl and HBr. During the daytime, the reaction of HCl and HBr with OH radicals lead to significant production of atomic Cl and Br, up to 1.7×10<sup>4 </sup>cm<sup>-3 </sup>s<sup>-1</sup>and 7.9×10<sup>4 </sup>cm<sup>-3 </sup>s<sup>-1</sup>, respectively. The production rate of atomic Br (via HBr + OH) are 2-3 times higher than that of atomic Cl (via HCl + OH), highlighting the potential importance of bromine chemistry in the urban area. Furthermore, our observations of elevated HCl and HBr may suggest an important recycling pathway of halogen species in inland megacities, and may provide a plausible explanation for the widespread of halogen chemistry, which could affect the atmospheric oxidation in China.</p>