Advanced sensitivity analysis using automation simulation model: Towards digital twin

현재 공정 운영에 있어서 스마트 팩토리와 같은 빅데이터 기반 인공지능 적용 기술이 발전함에 따라 Digital twin (DT) 기술이 대두되고 있다. DT 시스템을 통해 공정 설계를 위한 계획 수립부터 운영, 관리, 유지·보수 및 조기 대응 등에 대해 사전에 시뮬레이션 검증과 시스템 운영 중 최적화 수행, 미래 상황 예측, 사후 문제 분석 등이 가능하다. 이를 이용하여 디지털 차원에서 공정 조건 최적화 모델을 구축하고, 생산량 및 에너지효율과 같은 공정 효율을 극대화한 정교한 예측 및 분석을 수행할 수 있다. 본 연구에서는 Aspen plus 공정 모사 프로그램을 사용하여 모델링 된 고로가스 기반 메탄올 생산 공정에 Python 프로그래밍을 이용해 공정 내 recycle stream과 purge gas stream의 split ratio를 변수로 설정해 최적 공정 값을 찾는 DT 지향 automation simulation model for methanol production을 설계하였다. 설계한 모델은 최적 공정 값 도출뿐만 아니라 변수 범위에 따른 제품 생산량과 공정 에너지 데이터를 확인할 수 있으며 이를 시각화 하여 표현할 수 있다. 이 모델은 본 연구의 공정 이외에도 다양한 공정의 최적화 시뮬레이션 모델에 기여하며, DT 시스템 적용에 대한 가능성을 보여준다.2

Arteriovenous malformation of the external ear: a clinical assessment with a scoping review of the literature

Abstract Introduction: Auricular Arteriovenous Malformation of the external ear is a rarely encountered disease; in particular, arteriovenous malformation arising from the auricle, with spontaneous bleeding, has seldom been reported. Objective: In the current study, we report an unusual case of late-onset auricular arteriovenous malformation originating from the posterior auricular artery that was confirmed by computed tomographic angiography. The case was successfully managed by pre-surgical intravascular embolization followed by total lesion excision. Prompted by this case, we also present a scoping review of the literature. Methods: A case of a 60 year-old man with right auricular arteriovenous malformation treated in our tertiary care center, and 52 patients with auricular arteriovenous malformation described in 10 case reports and a retrospective review are presented. Auricular arteriovenous malformation can manifest as swelling of the ear, pulsatile tinnitus, pain, and/or bleeding. On physical examination, a pulsatile swelling and/or a tender mass is evident. When arteriovenous malformation is suspected, the lesions should be visualized using imaging modalities that optimally detect vascular lesions, and managed via embolization, mass excision, or auricular resection. Effectiveness of the various diagnostic methods used and the treatment outcomes were analyzed. Results: Various imaging modalities including Doppler sonography, computed tomographic angiography, magnetic resonance angiography, and/or transfemoral cerebral angiography were used to diagnose 38 cases reported in the literature. In another 15 cases, no imaging was performed; treatment was determined solely by physical examination and auscultation. Of the total of 53 cases, 12 were not treated (their symptoms were merely observed) whereas 20 underwent therapeutic embolization. In total, 32 patients, including 1 patient who was not treated and 10 with persistent or aggravated arteriovenous malformation after previous embolization, underwent mass excision or auricular resection depending on the extent of the lesion. No major postoperative complication was recorded. The postoperative follow-up duration varied from 1 month to 19 years, and only one case of unresectable, residual cervicofacial arteriovenous malformation was recorded. Conclusion: Auricular arteriovenous malformation is a rarely encountered disease, but should be suspected if a patient presents with a swollen ear and pulsatile tinnitus. Appropriate imaging is essential for diagnosis and evaluation of the extent of disease. As embolization affords only relatively poor control, total surgical removal of the vascular mass is recommended

Synergistic halide-sulfide hybrid solid electrolytes for Ni-rich cathodes design guided by digital twin for all-solid-State Li batteries

Halide solid electrolytes are a promising candidate for all-solid-state Li batteries (ASLBs) owing to their mechanical sintering ability and excellent (electro)chemical oxidation stability. However, these advantages are counteracted by the lower Li+ conductivities and higher specific densities compared with those of sulfides. Herein, a novel halide-sulfide hybrid catholyte design for Ni-rich layered oxide cathodes for ASLBs is reported. In a hybrid catholyte, Li3YCl6 (0.40 mS cm−1) coatings protect the surface of Li[Ni0.88Co0.11Al0.01]O2 while Li6PS5Cl (1.80 mS cm−1) serves as a Li+ highway. Li[Ni0.88Co0.11Al0.01]O2 cathodes with an optimal fraction of Li3YCl6, 10 wt% with respect to Li [Ni0.88Co0.11Al0.01]O2, substantially outperform electrodes using either Li6PS5Cl or Li3YCl6 in terms of capacity (202 vs. 171 or 191 mA h g−1 at 0.1C, respectively), initial Coulombic efficiency, rate capability, and cycling performance. The superiority of Li3YCl6 for interfacial stability in the Li3YCl6-coated electrode to the electrode without Li3YCl6 is confirmed by complementary analysis. Moreover, the digital twin model is successfully established and reveals electrically isolated Li[Ni0.88Co0.11Al0.01]O2 particles when 14 wt% Li3YCl6 is used. This insight leads to the development of a mixed conductor coating consisting of Li3YCl6 and carbon, further enhancing the performance: e.g., 134 vs. 53 mA h g−1 at 2C. © 2022 Elsevier B.V.FALS

Silent Vestibulopathy in Asymmetric Hearing Loss Can Be a Sign of a Cerebellopontine Angle Tumor

The presence of an ipsilateral cerebellopontine angle (CPA) tumor should be ruled out in patients with asymmetric sensorineural hearing loss (ASNHL). Although many patients with CPA tumors have ipsilateral vestibular hypofunction, some of them do not experience dizziness even with ipsilateral vestibular hypofunction. We analyzed the incidence of CPA tumors among patients with ASNHL without subjective dizziness based on the presence of vestibulopathy. We hypothesized that a patient with silent unilateral vestibular hypofunction (UVH) is more likely to be diagnosed with a CPA tumor. Among 157 subjects who underwent MRI for ASNHL, those who did not have “subjective dizziness” were selected. All subjects underwent hearing and vestibular function tests. UVH was diagnosed if canal paresis ≥ 25%, positive head-shake nystagmus, or gain of head-impulse test < 0.8 were detected. The diameters of the CPA tumors were measured along the petrosal ridge on the axial plane of MRI. Among the enrolled subjects, 44 (28.02%) were diagnosed with a CPA tumor. The 37 patients (84.1%) with a CPA tumor had silent UVH, while only 33 of the 113 patients (29.2%) without a CPA tumor had silent UVH (chi-square test, odds ratio = 12.8, p < 0.001). Silent UVH in patients with ASNHL may be a sign of a CPA tumor

New Cost‐Effective Halide Solid Electrolytes for All‐Solid‐State Batteries: Mechanochemically Prepared Fe 3+

Owing to the combined advantages of sulfide and oxide solid electrolytes (SEs), that is, mechanical sinterability and excellent (electro)chemical stability, recently emerging halide SEs such as Li3YCl6 are considered to be a game changer for the development of all-solid-state batteries. However, the use of expensive central metals hinders their practical applicability. Herein, a new halide superionic conductors are reported that are free of rare-earth metals: hexagonal close-packed (hcp) Li2ZrCl6 and Fe3+-substituted Li2ZrCl6, derived via a mechanochemical method. Conventional heat treatment yields cubic close-packed monoclinic Li2ZrCl6 with a low Li+ conductivity of 5.7 × 10−6 S cm−1 at 30 °C. In contrast, hcp Li2ZrCl6 with a high Li+ conductivity of 4.0 × 10−4 S cm−1 is derived via ball-milling. More importantly, the aliovalent substitution of Li2ZrCl6 with Fe3+, which is probed by complementary analyses using X-ray diffraction, pair distribution function, X-ray absorption spectroscopy, and Raman spectroscopy measurements, drastically enhances the Li+ conductivity up to ≈1 mS cm−1 for Li2.25Zr0.75Fe0.25Cl6. The superior interfacial stability when using Li2+xZr1−xFexCl6, as compared to that when using conventional Li6PS5Cl, is proved. Furthermore, an excellent electrochemical performance of the all-solid-state batteries is achieved via the combination of Li2ZrCl6 and single-crystalline LiNi0.88Co0.11Al0.01O2. © 2021 Wiley-VCH GmbH1

Single- or Poly-Crystalline Ni-Rich Layered Cathode, Sulfide or Halide Solid Electrolyte: Which Will be the Winners for All-Solid-State Batteries?

Two newly emerging materials for application in all-solid-state batteries, namely, single-crystalline Ni-rich layered oxide cathode and halide solid electrolyte (SE), are of utmost interest because of their superior properties (good microstructural integrity and excellent electrochemical oxidation stability, respectively) to conventional polycrystalline layered oxides and sulfide SEs. In this work, four electrodes employing single- or polycrystalline LiNi0.88Co0.11Al0.01O2 (NCA) and Li3YCl6 or Li6PS5Cl0.5Br0.5 are rigorously characterized by complementary analyses. It is shown that the synergy of employing cracking-free single-crystalline NCA and oxidation-tolerable Li3YCl6 can be achieved by considering intercoupled engineering factors that are prone to overlook, such as size, lightness, and mixing of particles. Accordingly, the highest level of performances in terms of discharge capacity (199 mA h g(-1) at 0.1C), initial Coulombic efficiency (89.6%), cycling performance (96.8% of capacity retention at the 200th cycle), and rate capability (130 mA h g(-1) at 4C) are demonstrated at 30 degrees C. Severe side reactions occurring at the Li6PS5Cl0.5Br0.5/NCA interfaces are also quantified and probed. Importantly, an overlooked but significant contribution of the side reaction of Li6PS5Cl0.5Br0.5 to the detrimental electrochemo-mechanical degradation of polycrystalline NCA is revealed for the first time by postmortem scanning electron microscopy and operando electrochemical pressiometry measurements

Na2ZrCl6 enabling highly stable 3 V all-solid-state Na-ion batteries

Halide solid electrolytes (SEs) are emerging as an alternative to sulfide and/or oxide SEs for applications in all-solid-state batteries owing to the advantage fulfilling high (electro)chemical stability and mechanical sinterability at the same time. Thus far, the developments in halide SEs have focused on Li+ superionic conductors. Herein, the development of a new Na+-conducting halide SE, mechanochemically prepared Na2ZrCl6 (1.8 × 10−5 S cm−1 at 30°C) with excellent oxidative electrochemical stability, is described. A trigonal crystal structure with the P3¯m1 symmetry is successfully identified by the Rietveld refinement of X-ray diffraction. Additionally, the bond valence sum energy level calculations disclose one-dimensional preferable Na+-diffusion channels in Na2ZrCl6. It is to be noted that despite the rather low Na+ conductivity of Na2ZrCl6, NaCrO2 electrodes that uses Na2ZrCl6 in NaCrO2/Na-Sn all-solid-state Na-ion batteries demonstrate an exceptionally high initial Coulombic efficiency of 93.1% and a high reversible capacity of 111 mA h g−1 at 0.1C and 30 °C (98.4% and 123 mA h g−1 at 60 °C), highlighting the excellent electrochemical stability of Na2ZrCl6. © 2021 Elsevier B.V.1