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Strong-field ionization of CH3Cl using femtosecond laser pulses, and the subsequent two-body dissociation of CH3Cl2+ along Hn+ (n = 1–3) and HCl+ forming pathways, have been experimentally studied in a home-built COLTRIMS (cold target recoil ion momentum spectrometer) setup. The single ionization rate of CH3Cl was obtained experimentally by varying the laser intensity from 1.6 × 1013 W cm−2 to 2.4 × 1014 W cm−2 and fitted with the rate obtained using the MO-ADK model. Additionally, the yield of Hn+ ions resulting from the dissociation of all charge states of CH3Cl was determined as a function of intensity and pulse duration (and chirp). Next, we identified four two-body breakup pathways of CH3Cl2+, which are H+ + CH2Cl+, H2+ + CHCl+, H3+ + CCl+, and CH2+ + HCl+, using photoion–photoion coincidence. The yields of the four pathways were found to decrease on increasing the intensity from I = 4.2 × 1013 W cm−2 to 2I = 8.5 × 1013 W cm−2, which was attributed to enhanced ionization of the dication before it can dissociate. As a function of pulse duration (and chirp), the Hn+ forming pathways were suppressed, while the HCl+ forming pathway was enhanced. To understand the excited state dynamics of the CH3Cl dication, which controls the outcome of dissociation, we obtained the total kinetic energy release distributions of the pathways and the two-dimensional coincidence momentum images and angular distributions of the fragments. We inferred that the Hn+ forming pathways originate from the dissociation of CH3Cl dications from weakly attractive metastable excited states having a long dissociation time, while for the HCl+ forming pathway, the dication dissociates from repulsive states and therefore, undergoes rapid dissociation. Finally, quantum chemical calculations have been performed to understand the intramolecular proton migration and dissociation of the CH3Cl dication along the pathways mentioned above. Our study explains the mechanism of Hn+ and HCl+ formation and confirms that intensity and pulse duration can serve as parameters to influence the excited state dynamics and hence, the outcome of the two-body dissociation of CH3Cl2+. [ABSTRACT FROM AUTHOR]

Numerical studies were conducted on the hydrodynamics of a freely falling rigid sphere in bounded and unbounded water domains to investigate the drag coefficient, normalized velocity, pressure coefficient, and skin friction coefficient as a function of dimensionless time. The bounded domain was simulated by bringing the cylindrical water container's wall closer to the impacting rigid sphere and linking it to the blockage ratio (BR), defined as the ratio of the projection area of a freely falling sphere to that of the cross-sectional area of the cylindrical water container. Six cases of bounded domains (BR = 1%, 25%, 45%, 55%, 65%, and 75%) were studied. However, the unbounded domain was considered with a BR of 0.01%. In addition, the kk-ω shear stress transport (SST) turbulence model was used, and the computed results of the bounded domain were compared with those of other studies on unbounded domains. In the case of the bounded domain, which has a higher value of BR, a substantial reduction in normalized velocity and an increase in the drag coefficient were found. Moreover, the bounded domain yielded a significant increase in the pressure coefficient when the sphere was half-submerged; however, an insignificant effect was found on the skin friction coefficient. In the case of the unbounded domain, a significant reduction in the normalized velocity occurred with a decrease in the Reynold number (Re), whereas the drag coefficient increases with a decrease in Reynolds number. [ABSTRACT FROM AUTHOR]

Climate change and global warming are the visible consequences of the increased amount of carbon dioxide (CO2) in the atmosphere. Among the various sources of anthropogenic CO2 emission, the diesel engine has a significant contribution. The development of a reliable system to efficiently minimize CO2 emissions from diesel engines to the safest level is lacking in the open literature. Therefore, a comprehensive multidisciplinary approach has been applied in this paper to investigate the efficacy of the post-combustion carbon capture (PCC) process for the diesel engine. The experiments have been performed on the exhaust of a direct injection diesel engine at five different brake powers with blends of aqueous ammonia (AQ_NH3), monoethanolamine (MEA), N,N-dimethylethanolamine (DMEA), and 1-ethyl-3-methylimidazolium tetrafluoroborate (C2mim BF4) ionic liquid (IL) as an absorbent for CO2 capture. The reaction mechanism of these absorbent with CO2 are also studied by the geometrical, energetical, MESP, frontier molecular orbitals, and NBO analysis using the first-principles density functional theory (DFT) calculations. The maximum CO2 absorption efficiency of almost 97% was achieved for the blend consisting of 67% of AQ_NH3 and 33% of MEA. Moreover, AQ_MEA and blend of AQ_NH3, DMEA, and C2mim BF4 ionic liquid showed 96% and 94% CO2 absorption efficiency, respectively. [ABSTRACT FROM AUTHOR]

The flow fields around a freely falling rigid sphere slamming onto a water surface in the bounded and unbounded domains were investigated using the shear stress transport k − ω improved delayed detached eddy simulation model. Based on the velocity of the sphere for all the domain cases, the Reynolds number was set equal to 106 in the investigation. The bounded domain was simulated by moving closer the wall of the water container from all around to the impacting location of rigid sphere and correlating it to the blockage ratio (BR). Two cases of bounded domains (BR = 45% and 70%) and a single case of the unbounded domain (BR = 0.01%) were studied. This study focused on analyzing the flow field when the sphere begins to impact the water until it is completely submerged. For BR = 70%, the mixing of air and water was observed in the wake region after making the complete submergence of the solid rigid sphere. In contrast, no such mixing was observed for other cases. The boundary layer reveals an increase in velocity and wall effect in the case of the bounded domain as compared to the unbounded domain. Higher magnitude of boundary layer thickness was achieved in the case of the unbounded domain as compared to the bounded domain. The Q and λ2 were used for vortex identification, and both the criteria were found to agree well with each other. [ABSTRACT FROM AUTHOR]

Strong-field ionization induces various complex phenomena like bond breaking, intramolecular hydrogen migration, and bond association in polyatomic molecules. The H-atom migration and bond formation in CH3OH induced by intense femtosecond laser pulses are investigated using a Velocity Map Imaging (VMI) spectrometer. Various laser parameters like intensity (1.5 × 1013 W cm−2–12.5 × 1013 W cm−2), pulse duration (29 fs and 195 fs), wavelength (800 nm and 1300 nm), and polarization (linear and circular) can serve as a quantum control for hydrogen migration and the yield of Hn+ (n = 1–3) ions which have been observed in this study. Further, in order to understand the ejection mechanism of the hydrogen molecular ions H2+ and H3+ from singly-ionized CH3OH, quantum chemical calculations were employed. The dissociation processes of CH3OH+ occurring by four dissociative channels to form CHO+ + H3, H3+ + CHO, CH2+ + H2O, and H2O+ + CH2 are studied. Using the combined approach of experiments and theory, we have successfully explained the mechanism of intramolecular hydrogen migration and predicted the dissociative channels of singly-ionized CH3OH. [ABSTRACT FROM AUTHOR]

The influence of the length of the alkyl chain and water molecules on the hydrogen-bond interaction of the chloride anion and imidazolium-based cation of the ionic liquid (IL) Cnmim Cl (where n = 2, 4, 6, 8, and 10) was investigated by combining attenuated total internal reflection infrared (ATR-IR) spectroscopy and density functional theory (DFT) calculations. Here, for the first time, the conformational isomerism of the alkyl chain of Cnmim Cl (n = 2, 4, 6, 8, and 10) is identified by marker IR bands. The IR peak at 1470 cm−1 related to the alkyl chain vibration exhibits a significant perturbation in its intensity and further shows a red shift upon increasing alkyl chain length. This indeed might be a marker IR band for conformational isomerism and also an indication of the interaction of the alkyl chain with the chloride anion. Further, in the C–H vibration region of the IR spectra, a significant variation of the IR intensities was observed for the νs(CH2) and νas(CH2–CH3) modes at 2931 and 2976 cm−1, respectively. These bands can be considered as further markers for conformational isomerism of the alkyl chain. Moreover, the peak at 2976 cm−1 assigned to an alkyl chain vibration reveals the maximum red shift of 20 cm−1 for n = 10, which suggests charge redistribution among ion-pairs as a result of the alkyl chain variations. Noticeably, the C2–H vibration does not show any significant change of its wavenumber position, suggesting that the alkyl chain length does not interfere with the hydrogen bond interaction between C2–H and the Cl anion. This was also evident from the DFT-calculated bond strength between C2–H and Cl, which remains unchanged upon varying the alkyl chain length. In aqueous solutions, blue shifts of the v(C2–H) band by +65, +60, +67, +62 and +62 cm−1 for Cnmim Cl (n = 2, 4, 6, 8, and 10) are observed, respectively. These results point to a weakening of the hydrogen bond between cation and anion, which is also supported and validated by results of the solvent (water) effect obtained using the polarized continuum model (PCM) of the DFT calculations. [ABSTRACT FROM AUTHOR]

This paper reports investigations related to addressing the cause of pinion teeth deformation of a helical reduction gearbox in a kraft process. The American Gear Manufacturers Association (AGMA) design methodology was employed to determine the safety factor under bending and surface fatigue strengths of a pinion and gear at two operating loads (3 and 3.75 MW). In addition, finite element analysis (FEA) of the pinion and gear assembly was also performed to check the misalignment (due to deformation) at 3.75 MW load. Based on the investigations presented herein, it is found that the pinion portion near the thrust disc became excessively deformed at the axial thrust corresponding to the 3.75 MW load, causing misalignment that resulted in the plastic deformation of the pinion teeth. [ABSTRACT FROM AUTHOR]

We present a study of the impact of water on the size‐ and electronegativity‐dependent hydrogen bonds between cation and anion of imidazolium‐based ionic liquids (ILs) with halide anions. We have combined Raman spectroscopy with density functional theory (DFT) computations to characterize the intermolecular associations of cation–anion–water moieties. The Raman band at ~1,422 cm−1, which is assigned to the ν(N─CH2─CH3) vibration of the ethyl chain in the neat ion pairs (pure ion pairs), is blue shifted by +7, +4, and +3 cm−1 for 1‐ethyl‐3‐methylimidazolim (C2mim) cation‐based C2mim X ion pairs with X = Cl, Br, and I, respectively, in a water‐rich environment. Simultaneously, upon dilution, a new peak at ~1,438 cm−1 starts to appear at the high‐wavenumber side with continuously increasing intensity. These significant perturbations of the ν(N─CH2─CH3) vibrational mode in water environment are a clear indication of the change in the alkyl chain conformation. Further, the relative intensities of the Raman bands at ~2,946 and ~2,950 cm−1 corresponding to νs (CH2) and νas (CH3) of the ethyl chain, respectively, were significantly changed upon dilution, which also confirms the conformational change of the alkyl chain. The Raman band belonging to the C4/5─H stretch mode was significantly blue shifted by +33, +41, and +42 cm−1 going from the studied neat ion pairs having Cl, Br, and I anions to the corresponding water mixtures, respectively. Significant changes were also observed for the ν(C2─H) vibrational mode of the ion pairs in water environment; here, we observed blue shifts of +60, +51, and +50 cm−1 for ion pairs having Cl, Br, and I anions, respectively. These results confirm the weakening of the ion‐pair interaction due to the interaction with water molecules. In contrast to the ILs with halide anions, C2mim BF4 does not show any variation in the Raman peak positions upon dilution. Experimental results are nicely supported by the results of DFT calculations, and a sensible connection was established. [ABSTRACT FROM AUTHOR]

Summary: For the diagnosis of pulmonary tuberculosis positivity of the sputum for acid fast bacilli is considered confirmatory. In such cases sometimes the other associated clinical condition may go undiagnosed. We are reporting case report in which the sputum for AFB positive male presented with the raised hemidiaphragm. [Copyright &y& Elsevier]

Abstract: Appearance of new opacity on the X-ray may simulate a disease and lead to the battery of test to confirm the disease. We are reporting case report when the patient with pleural effusion presented with the new opacity on follow up chest X-ray. [ABSTRACT FROM AUTHOR]

Summary: Musculoskeletal tuberculosis which is less frequently encountered is the commonest form of extrapulmonary tuberculosis. Occasionally tuberculosis may involve the chest wall causing rib destruction. Usually the associated lesion in the pleuro-pulmonary region is found. We report a case of tubercular osteomyelitis of the rib causing its destruction with no associated lesion in lung parenchyma or associated lymphadenopathy. Patient was successfully managed by anti-tubercular drugs. [Copyright &y& Elsevier]

The article discusses the case of a 26-year-old female presented with fever and cough of one month's duration. Result of the patient's chest radiograph shows the presence of coarse miliary tubercles in both lungs and subcutaneous emphysema on the right side. The patient was diagnosed with miliary tuberculosis with pneumomediastinum and subcutaneous emphysema. It defines pneumomediastinum as the presence of air in the mediastinum.

Background: Interspinous devices were introduced in the field of spine surgery as an alternative to traditional pedicle screw fixation in selected patients for treatment of spinal stenosis and fixation. These devices designs have evolved from non-fixated extension blocks to sophisticated interspinous fixation devices (IFDs). There is an absence of literature comparing the biomechanical fixation strength of different IFD plate designs and the role of set screw locking systems. The aim of this study was to evaluate fixation strengths by bench testing static disassembly and pullout strength of two dissimilar IFD designs and locking mechanisms. We hypothesized that the InSpan (InSpan LLC, Burlington, MA, USA) dual-locking symmetrically IFD plate designed will have stronger fixation than the Aspen (ZimVie, Parsippany, NJ, USA) single-locking asymmetric IFD plate design., Methods: We conducted two biomechanical bench tests to evaluate the load to failure locking characteristics of symmetrical InSpan and asymmetrical Aspen IFD designs. Static pullout testing involved locking each IFD to the stainless steel and 40 pcf cellular polyurethane foam and measuring pullout load and displacement six times. Seven InSpan and two Aspen IFDs (including the "used" IFDs from the pullout testing) underwent static disassembly tests using a pair of disassembly fixtures positioned between the IFD plates to measure disassembly force and displacement. All tests were performed under ambient conditions using an INSTRON 8874 Bi-Axial Tabletop Servohydraulic Dynamic Testing System (INSTRON, Norwood, MA, USA), and data was collected at a 0.2 mm/s displacement control rate until the test was stopped when there was a drop in the continuously increasing force against resistance (gross failure)., Results: The InSpan IFD experienced 94.81% higher resistance to pullout compared to the Aspen IFD in static pullout testing (P<0.05), owing to its notably larger footprint area of 69.8%. Gross failure for both IFD implant designs occurred at the foam block-block interface. In static disassembly testing, pristine InSpan required 60.7% higher force over pristine Aspen and 401.3% for "used" IFDs. Gross failure was characterized by the gradual distraction of the plates and material removal at the set screw contact points. Implant failure at the block-implant interface emphasized the pivotal role of teeth design and the contact surface area of the plates in ensuring stability., Conclusions: The dual-locking symmetrical InSpan IFD outperformed single-locking asymmetric Aspen IFD in both static disassembly and pullout bench tests. This highlights the benefits of InSpan's improved design and its potential for enhanced long-term stability in spinal fixation applications., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jss.amegroups.com/article/view/10.21037/jss-24-13/coif). K.R.C. reports that he is the cofounder and CEO of KIC (Kingsley Investment Company) Ventures and has ownership shares in the company. V.L. is an employee of LESSpine, a for-profit medical device company. E.S. and W.M.C. have ownership shares in (Kingsley Investment Company) Ventures. The other authors have no conflicts of interest to declare., (2024 AME Publishing Company. All rights reserved.)

Strong-field ionization of CH 3 Cl using femtosecond laser pulses, and the subsequent two-body dissociation of CH 3 Cl 2+ along H n + ( n = 1-3) and HCl + forming pathways, have been experimentally studied in a home-built COLTRIMS (cold target recoil ion momentum spectrometer) setup. The single ionization rate of CH 3 Cl was obtained experimentally by varying the laser intensity from 1.6 × 10 13 W cm -2 to 2.4 × 10 14 W cm -2 and fitted with the rate obtained using the MO-ADK model. Additionally, the yield of H n + ions resulting from the dissociation of all charge states of CH 3 Cl was determined as a function of intensity and pulse duration (and chirp). Next, we identified four two-body breakup pathways of CH 3 Cl 2+ , which are H + + CH 2 Cl + , H 2 + + CHCl + , H 3 + + CCl + , and CH 2 + + HCl + , using photoion-photoion coincidence. The yields of the four pathways were found to decrease on increasing the intensity from I = 4.2 × 10 13 W cm -2 to 2 I = 8.5 × 10 13 W cm -2 , which was attributed to enhanced ionization of the dication before it can dissociate. As a function of pulse duration (and chirp), the H n + forming pathways were suppressed, while the HCl + forming pathway was enhanced. To understand the excited state dynamics of the CH 3 Cl dication, which controls the outcome of dissociation, we obtained the total kinetic energy release distributions of the pathways and the two-dimensional coincidence momentum images and angular distributions of the fragments. We inferred that the H n + forming pathways originate from the dissociation of CH 3 Cl dications from weakly attractive metastable excited states having a long dissociation time, while for the HCl + forming pathway, the dication dissociates from repulsive states and therefore, undergoes rapid dissociation. Finally, quantum chemical calculations have been performed to understand the intramolecular proton migration and dissociation of the CH 3 Cl dication along the pathways mentioned above. Our study explains the mechanism of H n + and HCl + formation and confirms that intensity and pulse duration can serve as parameters to influence the excited state dynamics and hence, the outcome of the two-body dissociation of CH 3 Cl 2+ .

Introduction Based on the anatomy of the frontal horn, a stereotactic ventriculostomy guidance system that does not need an elaborate setup and is suitable for ventricles of all sizes was developed. The objective of this paper is to describe this system and present the results of a cadaveric study in which this system was used. Method The system has a midline-based plate that is contoured to snugly fit the top of the head. It has two probe holders, one on each side at pre-set angles in coronal and sagittal planes, which enables the probe holders to point at the foramen of Monro. A cadaver study was done on eight donors. First, using the guidance system a 1.4 mm endoscope was inserted into the right frontal horn through a twist drill hole. Next, the scope was inserted into the right frontal horn on the same donors using the freehand method. Result With the guide, all eight ventricles were entered into on the first trial, and the foramen of Monro was visible end-on. With freehand technique: six ventricles were entered on the first try; however, the foramen of Monro was visible end-on only in one. In the other two, two to three attempts were needed. The guide facilitated 100% visibility for the end-on visibility of the foramen of Monro upon insertion and the results were statistically significant with t=7, df=7, p-value=0.000106. Conclusion This is a simple system, which is easy to use. The cadaveric study showed a high degree of accuracy to access the ventricles. The data shows significant improvement compared to the freehand technique., Competing Interests: A patent has been issued for the device studied in this manuscript. Arun A. Patil and Deepak K. Pandey have their name on the patent titled "Ventricular guide for ventriculostomy"., (Copyright © 2022, Patil et al.)

Introduction: Generally, interspinal distractor fixation devices are used for severe low back pain associated with neurogenic claudication, and radiculopathy with central or lateral recess stenosis and/or foraminal narrowing. In this paper, the authors result in cases of severe low back pain and lumbar radiculopathy in whom this device was used with excellent results., Method: This is a retrospective study. Patients were contacted via phone call and their pain score and other data were recorded at different timelines. The final data presented in this paper are the data collected at the final follow-up that ranges from 14 months to 24 months. Surgeries were performed in the outpatient setting and although no identifiable patient information is included in this paper, yet, patients were asked for their verbal consent. The patient data are only included if verbal consent was obtained., Results: Over the past 24 months, 13 patients with disc protrusion and/or central and/or foraminal spinal stenosis were treated with this procedure. Follow-up ranges from 14 months to 24 months with a median of 19 months, male/female ratio of 6/7, and a median age of 68 years. There were no complications or reoperation. Statistical analysis showed significant improvement in the Numeric Pain Rating Scale (NPRS) for back and radicular leg pain (p-value = 0.000552 for back pain and p-value = 0.000291 for radicular leg pain)., Conclusion: The system reported in this paper is a solid fixation system that works both as a distractor and internal decompressor of the spinal canal. It is simple to use and safe. Though the number of patients is small, statistically significant improvement was reported at a median follow-up of 19 months., Competing Interests: The authors have declared financial relationships, which are detailed in the next section., (Copyright © 2021, Raikar et al.)

Introduction Anterior cervical discectomy and fusion (ACDF) is the gold standard for the treatment of cervical spondylosis. However, new techniques, technologies, and improved implants have aided surgeons in reducing operative time with enhanced patient outcomes. Impregnated hydroxyapatite polyetheretherketone (HA PEEK) cages (Arena-C HA®, LESspine Inc. Malden, MA) are one such option that has aimed to increase the fusion rate. The authors herein aimed to assess the use of HA PEEK interbody cages by looking at outcomes, complications, and radiographic fusion.  Methods The medical records of 41 consecutive patients undergoing single-level ACDF with impregnated HA PEEK cages (group 1) were compared to the control group of 47 patients who had single-level ACDF without impregnated HA PEEK cages (group 2). Outcomes assessed included Visual Analog Scale (VAS) neck, Neck Disability Index (NDI) scores, radiographic fusion, and complication rates.  Results Of the 41 patients in group 1 (HA PEEK), 48% were female population with a mean age of 58.5+/- 1.7 years and BMI 29.7+/-1.2 kg/m 2 . Of the 47 patients in group 2 (non-HA PEEK), 53% were female with a mean age of 54.3+/- 1.2 years and BMI 27.8+/-0.8 kg/m 2 . Using t-test, there was a statistically significant intergroup difference in two-year VAS neck and NDI scores, p=0.007, and p=0.001, respectively. Radiographic fusion occurred as early as three months in the HA PEEK group.  Conclusions This study has demonstrated the equivalence of impregnated HA PEEK cages in single-level ACDF. Significant improvements were seen in VAS and NDI scores in the HA PEEK group. There was no incidence of heterotopic bone formation or reaction to HA PEEK cages. Additionally, a trend toward fusion was seen in HA PEEK patients as early as three to five months compared to seven to eight months for the ACDF group. We conclude that HA PEEK cages can be safely placed with excellent outcomes. However, further studies are required to look at added benefits., Competing Interests: The authors have declared financial relationships, which are detailed in the next section., (Copyright © 2021, Chin et al.)

Purpose The sacroiliac joint (SIJ) is estimated to be a source of pain in 15%-30% of patients presenting for the evaluation of low back pain. The SIJ may develop symptoms in an estimated 43% of patients who have had previous lumbar fusion surgeries. With increased awareness of SIJ as a pain source and for those patients who have intractable pain and who fail nonoperative treatment, surgery to stabilize the SIJ is becoming more common. Thus multiple different technologies and techniques need to be evaluated. The purpose of this study is to report on the clinical and radiographic follow-up of percutaneous lateral-oblique sacroiliac joint fusion with a threaded compression screw performed in an outpatient ambulatory surgery center (ASC). Methods Three consecutive patients were chosen for this technique, and after completion, were followed for at least 24 months as part of a pilot study to see how they responded to the treatment. The medical charts of these patients were reviewed along with follow-up radiographs and computed tomography (CT) scans to assess for radiographic fusion designated as bridging bone across the SIJ with no signs of implant loosening such as haloes around the screws, change in position, or screw breakage. The SacroFuse (Sacrix LLC, Boston, MA) SIJ screws were 12 mm x 60 mm at S1 and 12 mm x 50 mm at S2 with threads for compressive fixation and cannulated for percutaneous placement over a guidewire. We evaluated patients' demographics, the pain visual analog scale (VAS) score, and the Oswestry Disability Index (ODI) preoperatively and postoperatively. Results Our first patient was a 51-year-old male body mass index (BMI) 33.3 kg/m 2 with a previous lumbar fusion. He underwent a two-staged SIJ fusion. The first surgery was done as an open direct lateral surgery, and the second stage was performed three months later using a direct percutaneous lateral-oblique technique for three months. The second and third patients, respectively, were 22-year-old female status prior L5-S1 anterior lumbar interbody fusion (ALIF) plus right posterior unilateral pedicle screws. She had a BMI of 38.3 kg/m 2 . The third patient was a 41-year-old male with a BMI of 29.5 kg/m 2 who underwent lateral-oblique bilateral percutaneous SIJ fixation. The latest CT imaging of each patient demonstrated increased bone density adjacent and within implants with intra-articular osseous bridging. There were no implant failures or complications. Conclusion This pilot study demonstrated the feasibility and effectiveness of a new percutaneous lateral-oblique SIJ fusion technique with a threaded compression screw done safely in an ASC. Patients demonstrated early pain relief and long-term fusion of their SIJ. We introduced the Sacrix line as a key fluoroscopic landmark for the success of this percutaneous technique., Competing Interests: The authors have declared financial relationships, which are detailed in the next section., (Copyright © 2021, Chin et al.)

Strong-field ionization induces various complex phenomena like bond breaking, intramolecular hydrogen migration, and bond association in polyatomic molecules. The H-atom migration and bond formation in CH3OH induced by intense femtosecond laser pulses are investigated using a Velocity Map Imaging (VMI) spectrometer. Various laser parameters like intensity (1.5 × 1013 W cm-2-12.5 × 1013 W cm-2), pulse duration (29 fs and 195 fs), wavelength (800 nm and 1300 nm), and polarization (linear and circular) can serve as a quantum control for hydrogen migration and the yield of Hn+ (n = 1-3) ions which have been observed in this study. Further, in order to understand the ejection mechanism of the hydrogen molecular ions H2+ and H3+ from singly-ionized CH3OH, quantum chemical calculations were employed. The dissociation processes of CH3OH+ occurring by four dissociative channels to form CHO+ + H3, H3+ + CHO, CH2+ + H2O, and H2O+ + CH2 are studied. Using the combined approach of experiments and theory, we have successfully explained the mechanism of intramolecular hydrogen migration and predicted the dissociative channels of singly-ionized CH3OH.

Hydrogen energy has received significant attention in the renewable energy sector due to its high energy density and environmentally friendly nature. For the efficient hydrogen generation from water, the hydrogen evolution reaction (HER) has to be optimized, which requires a highly efficient electrocatalyst. In this work, a hybrid structure of the ionic liquid (IL) 1-ethyl-3-methylimidazolium trifluoromethanesulfonate (C 2 mim TfO) and (TiO 2 ) n nanoclusters with n = 2-12 has been investigated in the pursuit of new catalyst materials for effective HER. We have employed state-of-the-art density functional theory (DFT) computations to depict the HER catalytic performance of IL/(TiO 2 ) n hybrid systems through Gibbs free energy (Δ G ) and an exchange-current-based "volcano" plot. We have explored the effect of the TiO 2 nanoclusters on the structural and electronic characteristics of the IL, calculating the adsorption energy, the energies of the highest occupied (HOMO) and lowest unoccupied molecular orbitals (LUMO), the HOMO-LUMO band gap E g , and the work function ϕ. The variation in size of the TiO 2 nanocluster in the IL/(TiO 2 ) n hybrid system was found to have a significant influence on the electronic properties. The obtained results suggest that the Δ G of the hydrogen adsorption is remarkably close to the ideal value (0 eV) for the IL/(TiO 2 ) 5 system, which also reflects from the volcano plot, suggesting that this complex is the best HER catalyst among the studied systems; it might be even better than the traditional Pt-based catalyst. Thus, the present work suggests ways for the experimental realization of low-cost and multifunctional IL-based hybrid catalysts for clean and renewable hydrogen energy production.