Stephen J Jenkins

Photograph of a wall-mounted oval plaque bearing a coat of arms, illuminated by varicoloured light streaming from a nearby stained glass window. The arms comprise four white lions in rampant posture positioned around a gold cross on a blue background. The cross has decorativ ends in the form of fleurs-de-lis. The whole is surrounded by scrollwork, surmounted by the head and hands of a crowned figure.

Arms of the Diocese of Durham, in Durham Cathedral. Azure a cross fleury or between four lions rampant argent. #StainedGlassSunday #Durham #Cathedral #Heraldry #CoatOfArms #Photography

Photograph of a wall-mounted oval plaque bearing a coat of arms, illuminated by varicoloured light streaming from a nearby stained glass window. The arms comprise four white lions in rampant posture positioned around a gold cross on a blue background. The cross has decorativ ends in the form of fleurs-de-lis. The whole is surrounded by scrollwork, surmounted by the head and hands of a crowned figure.

Arms of the Diocese of Durham, in Durham Cathedral. Azure a cross fleury or between four lions rampant argent. #StainedGlassSunday #Durham #Cathedral #Heraldry #CoatOfArms #Photography

Black and white photograph of a crenellated round tower, almost in silhouette against the sky. In the upper third of the frame, that sky is clear, but the lower two thirds are clouded; bright sunlight illuminates the boundary. The tower itself is rather squat, designed for defence against artillery, and to provide an artillery firing platform at its upper level.

Artillery Tower, Threave Castle. #CastleSaturday #Castles #ThreaveCastle #DumfriesAndGalloway #Medieval #LateMedieval #Architecture #Monochrome #BlackAndWhite #Photography

Black and white photograph of a crenellated round tower, almost in silhouette against the sky. In the upper third of the frame, that sky is clear, but the lower two thirds are clouded; bright sunlight illuminates the boundary. The tower itself is rather squat, designed for defence against artillery, and to provide an artillery firing platform at its upper level.

Artillery Tower, Threave Castle. #CastleSaturday #Castles #ThreaveCastle #DumfriesAndGalloway #Medieval #LateMedieval #Architecture #Monochrome #BlackAndWhite #Photography

Black and white photograph looking uphill through a scatter of tombstones and assorted funerary monuments. A stunted obelisk dominates the left foreground, while a dark shadow encroaches from the right of frame. The sky is largely clear with wispy clouds.

Glasgow Necropolis. #TombTuesday #Gravestones #Cemeteries #Necropolis #Glasgow #BlackAndWhite #Monochrome #Photography

Black and white photograph looking uphill through a scatter of tombstones and assorted funerary monuments. A stunted obelisk dominates the left foreground, while a dark shadow encroaches from the right of frame. The sky is largely clear with wispy clouds.

Glasgow Necropolis. #TombTuesday #Gravestones #Cemeteries #Necropolis #Glasgow #BlackAndWhite #Monochrome #Photography

Photograph looking up into the heart of a scalloped dome, sumptuously decorated in mainly blue and gold mosaic. From a central blue star, a chain descends toward the lower left of frame, while eight curved blue ribs, sporting zig-zag patterns in gold and white, emanate outward in all directions. Between these ribs are largely golden sections of mosaic, in which may be found foliate designs picked out in blue and white.

Dome of the Maqsura in the Mezquita at Cordoba. #MosaicMonday #Cordoba #Andalucia #Architecture #Photography

Photograph looking up into the heart of a scalloped dome, sumptuously decorated in mainly blue and gold mosaic. From a central blue star, a chain descends toward the lower left of frame, while eight curved blue ribs, sporting zig-zag patterns in gold and white, emanate outward in all directions. Between these ribs are largely golden sections of mosaic, in which may be found foliate designs picked out in blue and white.

Dome of the Maqsura in the Mezquita at Cordoba. #MosaicMonday #Cordoba #Andalucia #Architecture #Photography

Black and white photograph looking up a dark stone staircase toward a curved landing, the floor of which is not visible from this angle. The landing is bathed in light from the right and framed by tall stone arches offering an entrance from the left. Beyond these, a coffered wooden ceiling is visible, its rectangular sections following the curve of the landing. In the right foreground, an elaborate balustrade runs up the side of the stairs.

In the Palace of Charles V. #StaircaseSaturday #Alhambra #Granada #Andalucia #Architecture #Ceilings #Monochrome #BlackAndWhite #Photography

Black and white photograph looking up a dark stone staircase toward a curved landing, the floor of which is not visible from this angle. The landing is bathed in light from the right and framed by tall stone arches offering an entrance from the left. Beyond these, a coffered wooden ceiling is visible, its rectangular sections following the curve of the landing. In the right foreground, an elaborate balustrade runs up the side of the stairs.

In the Palace of Charles V. #StaircaseSaturday #Alhambra #Granada #Andalucia #Architecture #Ceilings #Monochrome #BlackAndWhite #Photography

🚨 Fully Funded PhD in Computational Chemistry

I’m recruiting a PhD student at the University of Surrey
for HeLix: Atomic-Scale Modelling of Advanced Helium Lithography.

Start: Oct 2026
Apply here:
surrey.ac.uk/fees-and-fun...

#PhD #ComputationalChemistry #SurfaceScience #Nanofabrication

Also, use of hashtags, such as #TombTuesday, #Photography, #Churches, etc may help more than you expect. In the absence of an algorithm, people do tend to follow these.

Very much interested, but visibility may be an issue. As someone else has pointed out, there is no algorithm, so if a follower is not actively watching at the moment you post, they may not see it at all. I tend to post once in the morning for the UK/Europe crowd, then repost late afternon for RoW.

Light streams through stained glass windows from top-right toward the lower-left of frame. Two identical panels, separated by a stone mullion and surrounded in stone, are each divided into an arched lower section and an upper quatrefoil section. These sections each feature a dark border enlivened with green leaves and white roses, within which there is white glass decorated with a spray of brown leaves. In the centre of each quatrefoil is a golden sunburst on a red background. Just above the centre of each arched window is a roundel defined by a dark border with green leaves and white roses, surrounding a golden crown of fleurs-de-lis on a red background.

Tyntesfield, Somerset. #StainedGlassSunday #Tyntesfield #Somerset #Sunshine #Photography

Snowing.

Light streams through stained glass windows from top-right toward the lower-left of frame. Two identical panels, separated by a stone mullion and surrounded in stone, are each divided into an arched lower section and an upper quatrefoil section. These sections each feature a dark border enlivened with green leaves and white roses, within which there is white glass decorated with a spray of brown leaves. In the centre of each quatrefoil is a golden sunburst on a red background. Just above the centre of each arched window is a roundel defined by a dark border with green leaves and white roses, surrounding a golden crown of fleurs-de-lis on a red background.

Tyntesfield, Somerset. #StainedGlassSunday #Tyntesfield #Somerset #Sunshine #Photography

Photograph of a seagull perched on a rounded rock at the seashore, occupying a small region just to the left of centre-frame. The rock is wet and stands amidst gentle waves in a blue sea. A little further out, the waves are breaking slightly with white caps. The bird is mainly white, with grey wings and a yellow bill. Both it and the rock are lit by direct sun from the right.

Gull on a Rock. #Flyday #Seagull #Birds #Nature #Wildlife #Seashore #Seaside #Beach #BirdPhotography #NaturePhotography #Photography

Photograph of a seagull perched on a rounded rock at the seashore, occupying a small region just to the left of centre-frame. The rock is wet and stands amidst gentle waves in a blue sea. A little further out, the waves are breaking slightly with white caps. The bird is mainly white, with grey wings and a yellow bill. Both it and the rock are lit by direct sun from the right.

Gull on a Rock. #Flyday #Seagull #Birds #Nature #Wildlife #Seashore #Seaside #Beach #BirdPhotography #NaturePhotography #Photography

News to me.

Fascinating. I was raised about three miles from Worlebury, so it was my local hillfort. Always wondered about those bodies...

Prediction of Double Dihydrogen Bonds at Two Semiconductor Surfaces We present first-principles calculations for hydrogen peroxide adsorbed on the monohydrogenated {001} surfaces of silicon and germanium. These calculations reveal a preference for binding through one ...

I’m very happy to announce the publication of our latest paper – “Prediction of Double Dihydrogen Bonds on Two Semiconductor Surfaces” #HydrogenPeroxide #Semiconductors #Silicon #Germanium #ChemSky #CompChemSky

Thanks!

Black and white photograph of a grave slab, the upper portion of which bears a latin inscription to the effect that this commemorates one Archibald Malcolm (also known as Archibald MacCallum) who died in 1685 in the 80th year of his age. In the middle is a coat of arms, supported from beneath by two angels, in which the shield bears four stag's heads surrounding a saltire that is decorated with five five-pointed stars. Above the shield is a helmet from which emanates a banner bearing the motto AD ARDUA TENDIT (it tends to difficulty). Immediately beneath the shield may be seen an hourglass and a heart, both on their sides. In the lowest portion of the slab on the left is a globe inscribed with the letters M, AM, and IM, while on the right there is an open book. More information, together with an excellent 3D scan of the slab may be found at https://blog.historicenvironment.scot/2022/10/scotlands-historic-gravestones/

Tombstone of Archibald Malcolm, Kilmartin Churchyard. The arms may be blazoned thus: Argent on a saltire azure between four stag's heads erased gules five mullets or (tinctures inferred). #TombTuesday #Gravestones #Cemeteries #Kilmartin #Heraldry #CoatOfArms #BlackAndWhite #Monochrome #Photography

We hope that future experiments may confirm the orientation of hydrogen peroxide molecules on these surfaces, supporting our interpretation that dihydrogen bonding is responsible. Meanwhile, we are now on the look-out for similar bonding in other related systems.

Also, we predict that since the molecule possess two hydrogen atoms it is likely that two such bonds will be formed. Although very weak, they are nevertheless strong enough to dictate the orientation that the molecule is most likely to adopt when bound to the surface at liquid nitrogen temperatures.

On the few occasions this kind of bonding has been seen before at surfaces, the negatively charged hydrogen atom usually belongs to the molecule and the positively charged hydrogen atom belongs to the surface. While the bonds we find here are not strictly unique, they are nonetheless very rare.

In our case, the silicon and germanium surfaces are sufficiently electropositive that they do, in fact, induce a negative charge on the hydrogen atoms bound to them. These can then take part in dihydrogen bonding with the positively charged hydrogen atoms from the hydrogen peroxide molecule.

The result is known as a dihydrogen bond, and they have been reported sporadically in the inorganic chemistry literature over the last thirty years or so. Examples from the surface science literature, however, have been few and far between.

Usually, the negatively charged atom in a hydrogen bond belongs to an electronegative species such as oxygen or nitrogen, for example, but very occasionally it can actually be a second hydrogen atom. The second hydrogen atom must bear a slight negative charge, which doesn’t happen all that often.

Now, there is a well-known form of bonding that often involves hydrogen atoms – known, unsurprisingly, as hydrogen bonding – where a hydrogen atom bound to an electronegative atom (such as oxygen) gains a slight positive charge and is attracted to an atom bearing a slight negative charge.